I bought one off of eBay, this one to be exact:
http://cgi.ebay.com/BLACK-RUBBER-HA...4|66:2|65:12|39:1|240:1309|301:1|293:1|294:50 (sorry about the huge URL, posting from my G1.)
It sounded great when I first looked at the post. Rubberized case? $6.00? Free shipping? Sign me up!
But in reality, this particular case was a huge let down. It is not "rubberized" by any stretch of the imagination. It is in fact smooth plastic. Also, the part that covers the buttons (home, back, etc) cracked the first time I put it on the phone.
In spite of these shortcomings, I was willing to put up with it until I got around to buying another since I waited forever for it to be shipped. That was, until I took it off to remove the battery. After I put the case back on the phone it was very loose, especially the part that goes around the screen.
The final straw came when I was walking out of a restaurant, holding my phone in my hand, and I watched in horror as my phone went tumbling towards the ground, leaving me holding nothing but the $6 cover. I'm sure you can imagine my anger.
So, needless to say, I discarded the offending cover as soon as I got home. Luckily my phone didn't sustain any serious damage, but still, I felt as if I should warn my fellow Androidians.
Please don't make the same mistaske as me.
Everytime a G1 hits the ground, an angel vomits.
Nobody wants that.