My answer to this is going to be somewhat different or non-traditional to almost all of your responses thus far except for @NoiseJockey. This is also going to be a bit of a long reply, but hopefully interesting and insightful. I know there are a lot of questions on here about how you get your start in a field like this and I think the experiences I've had are a bit unique compared to most. This is actually going to end up being a bit of a bio more than anything. It's mostly because I will always consider myself a student and every project I work on ends up influencing me further and further because I really love this craft.
Being 32 years old now (the beginning of 2011), of course I was deeply impacted by Ben Burtt's work on the Star Wars franchise, Walter Murch on THX1138, Frank Serafine on the original Tron, etc. but my true influence is a slight bit different.
The Sound: The major influence that got me into what I do now was a 80's-Current day musical group called "Skinny Puppy". They were an Experimental/Industrial/Avant-Garde Electronic group out of Vancouver, Canada that heavily experimented with sampling film, tv, their own found sounds and making very intense and cinematic music and soundscapes out of it along with synthesizers and a heavy amount of effects by really experimenting and pushing the envelope of how recording equipment was being used or what it was initially intended for. I guess you could say that besides using Oil Drums and other found sounds as percussion or effect loops or impacts and sweeteners in their compositions, at times they were even re-designing designed sounds that they sampled from films. They would take sounds from films and reverse them or drown them in reverb, pitch shifters, delays, flangers, phasers, distortion and so on. Guitar pedals and various esoteric effects mangling all these already interesting sounds to a new level. So they weren't straight up "lifting/stealing" the sounds, they were making something new out of them and making them their own and I was a huge fan.
There were also other artists using similar techniques, Public Enemy (The industrial strength sampling terrorists of the hip-hop world), Artists off of Zoth Ommog Records, Older Industrial like Psychic TV, SPK, Cabaret Voltaire, Dive and Etc. Stockhausen, Reich, Cage, Kraftwerk and other Early Avant-Garde composers up to modern day luminaries like Amon Tobin, Aphex Twin, Autechre, etc. (Yeah, I think we'd get along well @NoiseJockey). None as initially influential as Skinny Puppy though. My A-Ha! moment was thus sort of similar to @NoiseJockey.
The Effect (in absurd detail): When I was 15 years old I started my own musical project (am I actually admitting this?) one night when I was in a tiny recording studio (I mean this place was about 20ft x 20ft at most) that was owned by a punk rocker friend of mine's older brother. The studio mainly specialized in recording punk bands. I was a slight bit of a goth kid around that time (though mostly listening to Industrial and a lot various electronic music from Electro to Industrial to Techno, New Wave and Experimental) and true to the cliche, I had a book of poetry. We were also drinking quite a bit of vodka. *Side-Note: At this point in time I was more of a graphic based artist and a bit of a dabbler in other visual arts. Drawing, Sculpting, Photography, Etc. The first career I ever dreamed of having when I was a child was to be a comic book artist. *End Side-Note.
In this studio they also happened to have a server rack full of various guitar effects units and they also had a Korg DW-8000 synthesizer, a Roland Octapad drum set and a VCR. My friend asked me if I wanted to make a song and happily enough I said "sure", always being one interested in experimenting in new types of art. He introduced me to the various gear and gave me a brief description of what each piece does. Having a thorough interest in my favorite musicians recordings, I already had a pretty decent idea of the natural order of these things and a basic idea of what they all do. We played around for a while and I haphazardly designed/created and programmed some interesting sounds with the Octapads, DW-8000 and etc.
One of the movies in the studio was "Silence of the Lambs" and we scanned through it for something appropriately spooky to sample from it and ended up with a loop recorded into a Roland Guitar FX rack unit of Jodi Foster saying "Screaming, some type of screaming like a child's voice" that we looped over and over with a backwards reverb to make it sound uber-spooky and cool. We pitched it to the tempo we wanted and then proceeded to come up with more cohesive musical parts that we had played around with just before. At this point I was playing the part of producer more than performer since I wasn't a musician by any means at that point. I was more directing him with my ideas and descriptions. I did compose some synth lines and played them on the recording though. I did also have a decent sense of rhythm. We recorded this sort of sound collage/song to the two track analog tape machine and moved on to something more upbeat which I ended up singing over (horribly, I might add) and then we called it a night or just ended up passing out considering the obscene amount of vodka we drank in the process of this excursion.
The next morning I woke up on the floor of the studio with a cassette tape in my pocket (and quite a hangover). I went home and listened back to what we had created and it just totally blew my mind. We had created something out of nothing and in the end, the result was that we still had nothing. Well, nothing tangible besides the cassette as the physical carrier. I realized that we started with just these vibrations floating through the air and we manipulated them to our will and in the end we still only had vibrations floating through the air. It was an intangible piece of art that will forever morph and change based on mood, hearing abilities, listening environment and so on. It was a forever changing piece of art. It was like being a modern day Michaelangelo... only instead of marble we were carving our creations out of slabs of noise. From that moment on I knew I had found the ultimate art form (for me at least). I then promptly bought my first synth from a pawn shop and started a horrible band that got much better very quickly.
Two years later I found a local studio to work at. This studio was the Audio Playground Synthesizer Studio and Museum. We had well over 1000 synths and over 300 drum machines. The largest known collection of synths in the world actually. My first job there as an intern at 17 was to chop up and archive recordings of all these (mostly antique and classic) drum machines into one hits and loops. I also had to sketch out the machines, photograph them and document my sounds. Little did I know, this was my first bit of training into creating my own sound libraries. I helped the owner Alpha/Beta test and create synth presets for boutique and major synth manufacturers, I designed synth presets for and recorded the legendary Patrick Moraz and a whole slew of other artists. I assisted the owner in building the largest midi network in the world and I learned how to solder and do basic synth repair. We networked all the various studio rooms so you could patch a synth from any room into any other room. I worked there off and on for around 10+ years. I cut my teeth here in the mid 90's just as DAW's were starting to go somewhat mainstream and Opcode created the first real DAW. Opcode Studio Vision Pro. The first sequencer to incorporate MIDI and audio. Yamaha had also just released the O2R.
By the time I was 21 I got an audio post internship at the largest post house in the Southeast, Century III on the back lot of Universal Studios FL. because my girlfriend at the time was a 2D compositor there and the audio guy needed an assistant. I then learned more about audio post and sound design. I helped design sounds for the ride installations for Universal and Disney, I worked on a bunch of Industrial work for Lockheed Martin and started to do a little TV work as well. They eventually closed a few years after 9/11 and I then worked in a few other industries and worked in a few small studios, as a private studio planner and DAW builder. I also did some remixes for some releases and etc. until Full Sail University called me when I was about 28. They said they found my resume somewhere and wanted to interview me for a position as an Instructor in the Audio Post department of the Recording Arts program. I was hired on and I finally got that Full Sail experience I always wanted when I was 17 but could never afford. I learned a lot when I was there, met some amazing people, received some amazing training and got to spend 2.5 years sharing my extreme love for all things audio in some jaw-dropping and amazing studios that I also had the privilege of using when off the clock.
While working there I finally landed my first feature film job with a few co-workers in my department and I was lucky enough to take on the position of "Sound Designer". It was sort of a trial by fire and I was responsible for the major scenes and the core "sound" of the film (which was a horror film, so I got to experiment a lot and really dive in head first). I did roughly about 45-60 solid featured minutes of very extreme and in-depth sound design out of the entire 90m film (well over 500GB of all original, custom non-stock library material). We finished the entire film in about 5 weeks (which is obscene for a team of 5 people handling all of the entire Audio Post duties while also working about 48 hours full time at Full Sail. I also got to pre-dub all my sound design stems in surround.
About a month after that there were some layoffs and I ended up being one of them. I spent a few more months in Orlando, worked on a couple more feature films as a sound designer and then moved to NY to find work. I quickly realized NY is way overcrowded with people even more experienced that I was who were also out of work and righting for the same entry level/low paying jobs I was. I could hardly even find an internship position paying me more than turkey sandwiches and realized NY was a futile effort. I then moved to Denver (where I currently am) and I found more freelance work in 3 weeks than the 3 months I spent in NY. It's a modest market full of small scale Indy productions and a decent amount of advertising work and IT/Game development. Since being here I'm learning how to develop a freelance career since studios still aren't hiring due to the economy and I've started doing sound design for hardware and synth manufacturers. I'm developing my own sound libraries for a couple companies, doing a bit of local Audio Post work here and there and also concept designing a very extreme and versatile sound design plug-in for one of the software companies I do preset/sound design work for. So things are looking positive. I'd rather work for an employer since the business end isn't my strong suite and I'd love more feature film work. I really love the big scale crazy stuff where I get to experiment and innovate. I see this as a learning experience as well though. It's definitely teaching me my worth and how to be even more efficient.
All that being said... my initial focus and transition from experimental electronic music to film was just an obvious path for me. It just made sense since I was using similar techniques, but simply applying them to different forms of media in slightly different ways. I've unfortunately spent a lot of time starting over in new sectors of the industry and haven't been able to get a steady hold in one particular one just yet, but I also find that it's provided to be very useful and has taught me to think outside the box, be versatile and a bit of a jack of all trades. It's helped me in every situation I've been in since. Especially since it's always more than we sign up for or what we think the job entails. It's also helped me dive a bit further than simply entry level positions. I've had years of sound editing and design experience, just not on a feature film, but I was able to get into that position based on my other experiences and skill. Not many people get to jump the line like that on their first feature film and I got really lucky. My main focus in the long run is more sound design work for feature films, but sometimes I like the distraction of a sound library, musical project or developing plug-ins.
Wow, that was long. Sorry about that guys. Hopefully it was interesting. I desperately needed a break/distraction from an ADR/DX editing gig I'm not too enthusiastic about.