Ok, so for those of you with iPhones....
You have to check out pocket planes. In all honesty it's one of the most addicting mobile games I've ever played. You basically create and run your own airline, right from your pocket! The creators of this game are NimbleBit, and although the game may just be an 8-bit 2D game, it's seriously addicting.
For those who may already have the game, you can add me by friend code: 173N