and to be honest, it's not very good. You can't put random games on it (but that's not a problem on the Droid I guess), and the controls are very hard to use (I have big fingers, so it's quite akward). Part of the problem is the lack of proper gaming controls, but unless you use a portable console (or one of those Taco nGage phones) you won't get that on an android phone.
The one thing that could be cool though, if well done, are computer emulators with a keyboard (for adventure or rpg games for example). I would really love to see a good portable Apple IIe emulator (there is pomDS, which is ok, but has an ugly bug on the joystick control that makes lots of games unplayable).
[download a life]