a free (as in cost per txt, not necessarily a totally free app, though it would be nice), carrier independent, serverless p2p text messaging service, which ties seamlessly into android's MMS subsystem, so it can be utilized by any MMS client (the default one, Handcent, GO SMS, etc.). it should be transparent to the user, server free, encrypted, and free per text. ideally, it would use your regular number as your user ID, and as you text someone (at least for the first time), poll the swarm to check if the recipient is also using this app, and if not, routes to the standard carrier network instead. a nice feature would be if it could also take over Google Voice's SMS duties and make them available to other clients, as well as being able to use your GV# as your user ID, or as a carrier fallback. If you want to create your own client interface, it should be completely optional (I like Handcent for texting, thanks), but if you can outdo the current choices, I might use it.
I realize there's things like Kik, Beluga, Google Talk, Aim, etc, soforth, so-on, ad infinitum, ad naseum, but they all use their own username and login mechanism, they all force you to use separate clients (unless you use Trillian), and they all depend on a central (if distributed) server. all that takes setting up, knowing if each of your friends has one of them and which one, and then having several IM services running constantly on your phone (again, unless you have Trillian, which won't stay in memory, last I tried it).
this would streamline all of that down to a single app using just your phone number, and seamlessly switch to carrier MMS if necessary, making it much more likely for people to use.
oh, and I'll second the music transcription
edit: just had another thought. a MySpace client which isn't complete garbage. or better, a multi-social client better than t-mobile's poor offering (SocialBuzz)
