iPhone Pick: Galcon

I had gotten addicted to Galcon on the Mac, but the iPhone version is very much what you expect: a lot of twitch strategy in the palm of your hand. Basically you have a group of planets, you click on planets to send your armada to other planets and try to rule the galaxy. There's no resource allocation or unit distinctions - just click and go. It's simple but very fun.

It lacks a multiplayer mode, which is a bit of a shame as people make for far more interesting adversaries than the computer, but the game still manages to make for a decent challenge on the go. Also, the current version crashes occasionally on load - a problem that is currently plaguing a few iPhone apps. Hopefully a patch will resolve it.