Oh man, most people probably haven't heard about Firefly anyways. It was a tv series from the guy who made Buffy and Angel that was cancelled after less than one season aired. You can buy the series on dvd. It was cancelled because it was basically too good for the fools at Fox - they didn't get it. But ya, the setting in a nutz shell (from the guy who made the mod):

A "space Western" if you will. Western, Asian, and sci-fi themes blend in a convincing mix of what the future may be.

So basically you guys would have a ship and be traders or bounty hunters or whatever fits yer fancy. There's cities, other ships, homesteads, astroids, palaces, and shit like that for locations. And lot's of guns and fisticuffs. I'll prolly run it once and it will be disast0rz, but I wanna at least try.