My HTC Touch Pro2 (Windows Mobile) has that resolution. Verizon has already had a couple released 800x480 screens that run their BREW platform (LG EnV Touch). All are usable but none have the iPhone's hardware graphics acceleration. Kind of a shame, too.
EDIT: I should also mention that it cost me about $200 with renewal
EDIT: I should also mention that it cost me about $200 with renewal