I second the M-Edge cover recommendation. I have the original Amazon case and the M-Edge which costs the same price, and the M-Edge is much nicer. There are two varieties actually - the M-Edge Go! Jacket, which costs $30, and the Prodigy, which at $45 is slightly more padded and has the closure strap.
Personally, the one I'm using the most is the
Go! Jacket.