i've been playing vendetta a lot recently
it's an online only multiplayer game set in space
it has versions for linux, mac and windows
the homepage is:
http://vendetta.guildsoftware.com/
well worth the download time (25MB approx)
nb: this is a test game, not a finished release, but seems stable
and there's usually ppl online
the game is free while it is in test development, there are plans to have a charge when it goes into final release
