I also love the images at InterfaceLIFT. However, if you go back a year or so, you'll find that the photos don't have a selection for 800x480 from the dropdown box. I'm glad Hellaphone got updated with a selection for N800. I'm tired of having to use ImageMagick to resize/crop my images (even if it is a great command line utility).

I'll also suggest stock.xchng since there are a ton of royalty-free images there. You have to register for a free account, but after that you could spend months searching through all the images available. They don't have nice resize options like InterfaceLIFT, but you can again use Hellaphone.

And there's also this image repository created by another ITT member specifically for the NITs.