Is there a decent site for getting instrumental versions of popular songs?
 

I'm looking for an instrumental of King of Leon's Crawl at the moment but a decent site for this kinda thing would come in handy in the future.

Guess not then. :-\

You can usually get the instrumental of any rap or electro single because the single disc is usually the song, the instrumental and 1 or 2 remixes.

I recommend Soulseek for that.