I think It would be around the 2,600 mark. Thats based upon 200kb Images.
I just took a 1280x1024 photo (lots of colours) and saved it with jpeg compression of 82 (similar to that of my digital camera) and it came out at 130kb.
So you could probably get more images on 512mb (4032.9 images if they're all 130k)
I want to get a 512mb portable storage device (USB) so that when i go travelling i can store the vast amount of pictures i take on there (safely around my neck). Would hate myself if my camera got stolen and lost all my photos!!!
If anyone can suggest a quality sub-£250 digital camera lemme know!