I've used iSkin silicone cases with all my iPods but iSkin only makes cases for Apple products and Blackberries. So I sent them an email inquiring about a case for the Droid and this is what they said:
Maybe if enough people send them emails we can get a nice silicone case made for the Droid. You can check out their cases here iSkin Premium Accessories for iPhone iPod BlackBerry Mac and PC
Thank you for your interest in iSkin.
At the moment, we do not have any news or update with regards to releasing iSkin cases for the Motorola line. We will however take your inquiry into consideration as we are currently evaluating the market and hopefully we can release into the market an iSkin for your Motorolo Droid.