How scratchproof is the Touch Pro screen?

[sazer01]

The iPhone is pretty legendary for its high-end glass screen that is very resistant to pocket scratches or every day use scratches. On the other side, by Blackberries (Curve and Pro) nearly always scratched at the first contact with my keys, so I always protected them.

I'd prefer not to have to put a protective layer on top of my Touch Pro screen, so... how scratch resistant is it? Do minor scratches affect the viewing of your screen? I'm not talking about stomping it on the ground scratches, but just from every day pocket or purse banging around. It is iPhone sturdy (i.e., nearly scratchproof and doesn't need a protective layer) or is it easy to scratch up? Thx!