[eluser]CroNiX[/eluser]
Personally, I'd have it create a thumbnail using an image library (true thumbnail, not a large image displayed at a different size with css/image attributes) and store both the large image and the thumbnail. Use the thumbnail to click to get to the larger image. If you are just resizing large images via css you are wasting bandwidth and the time it will take to display that larger image. Not to mention an extra load on your server. Not a big deal unless you have a popular site with lots of visitors, which I presume is the end goal.