Sena just came out with this pouch type case for the Droid, the Ultraslim Pouch for Droid.
Made of authentic leather, it's claim to fame is that Sena claims it's the thinnest leather pouch made for the Droid, and who am I to argue? From videos I've watched, this IS a very thin case.
Per their website:
Light zero bulk protective layer
Soft velvet lining with stitching along opening
Thinnest pouch Sena offers
This does appear to be a very thin pouch!
You can check out a video of the same case, for that, um, other smart phone .
The case comes in lots of different colors, including black, white, red, tan, etc.