Just thought I would let those of you looking for cases know about this one I purchased on ebay:
NEW Black Velcro Cover Holster Case for Motorola Droid - eBay (item 190380215528 end time Apr-11-10 23:53:04 PDT)
I was a bit skeptical because it was so cheap, but the quality is nice. It has a secure belt loop fastener so you don't have to worry about it flying off your belt. It has a velcro closure as well. I'll be buying another one to have as a spare in case my current one doesn't last.