Originally Posted by
Dumpstergrub@gm
I like to wedge a rolled up t-shirt or rag in between the wheel and seatstay. It holds the wheel nice and tight as you torque it. Don't get it too loose or too tight though. Best advice i have is learn to navigate sheldon brown's site and you'll never really have to ask a question again.
http://sheldonbrown.com/singlespeed.html#tension
you don't need to wedge anything in there.
you should be able to tension it by hand, or just walk the wheel back in the dropouts...