To keep the widescreen ratio with 800x480 they would need something like 1200x720. Of course they are going to have other aspect ratios so I don't know.
Carrier: T-Mobile USA
Phone: Dell Venue Pro 16GB
"Ask not what your smartphone can do for you - ask what you can do for your smartphone. Ask not what developers will do for you, but what together we can do for the freedom of smartphones."