I want to combine two of these micropones into one stereo signal. This cable looks like the one suggested in this thread, but it seems like its meant for audio output. Do you suppose it could do the trick? I plan to use it on a laptop microphone port to play Ultrastar.
Input or output. It will work for either as it's just a cable. It all depends on what you hook it up to. It's hard to tell from the site just exactly what the output specs are for the mic. It says 3.5 - 6.3mm. I would email them and ask for the exact specs on the business end of that output connector.
There are, however, a number of things you should consider: Mic level and line level are totally different. The mic input port on a pc or mac has a built-in mic pre-amp to provide the necessary gain stage to get a decent signal. Without it, you will have no good signal coming in. You can't just plug a mic into a normal input and get a signal. It has to have some mic pre-amplification in the signal path.
Also, you won't be able to separately mix levels from the two mics. Whatever gain you have set for one will be used for the other.
Also, I don't know if the mic input port on a pc or mac's sound card or motherboard is a stereo-capable jack or just mono. You would need to know in order to get the correct cable and have it work as expected.
Assuming that the mic's output is 3.5mm and mono, you'll want your Y connector to be dual mono 3.5mm female to 3.5mm male stereo or mono, depending on the if the mic input port is stereo or mono, as mentioned above.
Since these cables are cheap, get one of each and see how it works out. Good luck with it.