I'll second GlennD's recommendation for
Bloodsucking Fiends (and
You Suck) by Christopher Moore. Those are both good lighthearted vampire stories (but they're not set in space, sorry).
Although, I think you might be better off reading Moore's
A Dirty Job. There's a
first chapter teaser up on his site, and it looks like there are teasers up for his other books, too. From the sounds of things, Christopher Moore is exactly what you're looking for right now.