I'm not sure that this quite counts as hardware, but here is a tip for all those worried about dropping the Treo 600 because of it being slippery:

Peel off the label on the back that has the serial number on it!

I had to do this, as it had started to come away, and was getting quite irritating. To my surprise I found the the glue underneath, whilst being almost completely incapable of sticking to plastic labels, will stick to just about anything else, and took quite a while to remove.

You'll never want to (or, indeed, be able to) put it down again.