The galaxy is HUGE, we all know that. We also know that the Imperium and Chaos Marines use warp drives to get around. So, how does everyone else do it?
I'll make a list so that you super-duper awesome 40K savants can simply add to it and what-not. I've included what little I know/assume.
Eldar: Some gate-thingies.
Dark Eldar: The same as Shiney-White Eldar, but spookier?
Tyranids: Space farts? (A joke)
Necrons:
Tau: Warp drives?
Orks:
Anything else to add? Oh yeah, thanks!