Turn on an Android OS phone, and that little yellow robot pops up all over the touchscreen like R2D2 on bionic steroids. A mini-chorus line of them shows up first, then just one robot decides to play hide and seek with you; there he is peeking out from the left side of the screen. Now he's upside down, waving at you with a tiny cyber-arm.

Strategy Wars: Android's Wide-Open Assault vs. Apple's Tight Grip