I don’t know if any of you have played any of team17’s Worms series, but they’re awesome.
Anyhow, Wormux is an open source equivalent available for OS X (as well as Linux, Windows, FreeBSD, and also available in a bootable livecd form), you should seriously consider checking it out.
[ Download it here ]
I’m hoping either team17 or the developers of Wormux come out with an iPhone version after the SDK launches. That would be fantastic.