I like to think the "straight" in "straight pool" means (from dictionary.com):
"Straight: unmodified or unaltered"
It's pool, in it's most straightforward and beautiful form.
Anyone know how it got it's name though?
Sounds like bobby had it closest then? I guess I get it... 'straight' means you can shoot in any order, as opposed to "rotation" where you rotate the order of your shots. If rotation is shooting in a kind of roundabout way, straight is firing directly at whatever ball you want. If you just shot the 5 you can go straight to the 8 ball or backwards to the 3 ball if you feel like it.