Ye Olde Blah

Android is Google's open source mobile platform. To promote it they're giving away $10 million in awards to fund Android development.
http://code.google.com/android/

The first deadline is April 14th (i think), and they'll give out 50 $25,000 awards, the winners of which then become elligible for a number of $250,000 and $100,000 grants.

Money aside, this is a great chance to get acquainted with making games and apps for a mobile platform - JAVA is required, OpenGL and hardware accelerometers and an Android emulator (Eclipse plugin) are available.

I'll be entering with an audio synth/drum machine (that's all i could think of and i'm well acquainted with direct audio manipulation in JAVA). But if you have games in java already, i would consider porting them.

If you have any good ideas for a mobile app, post them.

a platform for turnbased games, with one or two turnbased games included.

users can then play turn based games like chess, risk, battleships with each other on their mobile phone sending their turn details over the net when they have net access, or through bluetooth or by sms if they want.

i'm not sure how players would find each other.  but manual setting it up with your friend would be the most basic.  a server to host the player lists would be a bad idea for this sort of technology unless you're already a media giant imho. 
So perhaps some kind of automated searching for peers who are also searching method.  ie.. every phone playing with net access becomes a server and a host until the connection and unique address for the phones are sent to each other.  once the unique addresses have been exchanged they don't need to have any sort of direct connection - not for turn based games anyway.

You could in this way have multiple games running with the same or different people on the one phone.  depending on the game different sets of data would be stored on each phone, for example in battleships you'd have your board and your opponents mystery board and vice versa.

Given the system once you had the connection and packet transfer methods working sweet if you could "add games"(and others could) could it be a worthy thing?  dunno.

There's a P2P API using XMPP for multiuser apps through Google's servers.
http://code.google.com/android/toolbox/google-apis.html

I'd go for a Tamagotchi game. Should be popular with many folks, and the mobile presence makes it even more involved. Also, the clutchy controls and small screen are not a problem there ;)

You're right Job, I should have read more.

What about a translation tool.  Acts like those electronic language dictionaries.
Oh wait they probably have that already too haha damn google.