Some older skins from http://files.joat.co.nz/roadrunner/ were designed with 800x480 in mind. The BMV2/BMVA skins for instance were made to be used at 800x480 (native size) even though they're posted as 800x600 (which can be resized to 800x480). The difference is for instance that the buttons look "oval" on a 800x600 native screen, but are perfectly round in a 800x480 native screen (regardless of running the monitor at 800x480 or 800x600).
This kind of detail is pretty much unnoticeable on most skins though, so basically they will look just as good resized to 800x480 as they would on any other resolution.
I believe the Elite Lite skin is 800x480 and is by far my favorite skin right now