For FPS, there should be two iphone used, call them A and B, A positioned to the left and B positioned to the right. The left hand control iphone A, it will move the player character. if your fingers left the iphone, then the player character will jump. controlling movements is easy, move finger up to run, move finger down to walk backward, finger in the middle to stop, finger left and right to turn. The right hand control iphone B, this is where you shoot the monsters. You can double click to change weapon. For RTS, one good thing about iphone is it allow you to define the precise path that units will move. For example, you draw a curve on the iphone, then the unit will move in the curve that you draw. For selection of units, here is my thoughts: use two finger to draw a closed loop to select multiple units. One finger to select single unit.

That would be fun, but nobody has 2 iPhones.

Yeah, who is walking around with 2 iPhones! The RTS does sound fun though.