I have been working on a fairly large piece for several months now that I'm super excited about, though I can't talk much about it yet as there is a big element of surprise involved for the visitors. And another smaller, but very technically complicated, one that I am trying to get a residency for so that I can actually fund the darn thing. I so wish I could yap more about them right now. They will definitely be a lot of fun to discuss here after they've shown though. :)
There is loads of great stuff out there. I recently stumbled across this person's work and it's got me all kinds of drooling: http://zimoun.ch/
More on the radar of the general music-making population might be:
Giorgio Sancristoforo's audioscan pieces are spectacular. I'll be interviewing him soon for a new online sound art and sound design "mag" I'm launching soon. Very stoked to talk to him. Lately I've become really fascinated with grand scale outdoor stuff. http://www.gleetchplug.com/gleetchplug/Works.html
and Ableton's own Robert Henke has done some really gorgeous work too: http://www.monolake.de/installations/
Cycling '74's Projects page often has some interesting stuff to show: http://cycling74.com/project/
Harvestworks might also be a good place to check out as well: http://harvestworks.org/
There really is tons and tons out there of all shapes and sizes. A little search on Vimeo should yield a few hours of viewing pleasure.