This site works a lot better than Gimp to reduce photo file size
Online Image Optimizer: Optimize your GIFS, JPGS, and PNGS online.
Even the graphics and photos provided for affiliates are often at 300 dpi. I'm not at all interested in print quality. I just want a quick loading page and don't like wasting hard drive space.
Lately I've been using it for almost every page I put up.