I'm using two goodies from Waterfield in San Francisco, and I'm gaga about both of them.
First, their Ultimate Sleeve case -
http://sfbags.com/products/ipad-case...cases-ipad.php
and a fantastic Portable Muzetto bag to carry it around in -
http://www.sfbags.com/products/muzetto/muzetto.htm
If you're interested in the bag, too, make sure you get the Portable model; it was designed to fit the Ultimate Sleeve case. They're not cheap, but they'll last a lot longer than the iPad will. (This first model, anyway.)

I love 'em.