How are they optimized for the web?

Photoshop allows you to save them optimized for the web. What application were you using to make and save your images?

Look at the Yahoo User Interface (YUI) library. They have an experimental ImageLoader that loads images after the page has been completed. You can find it here:
http://developer.yahoo.com/yui/imageloader/

Since YUI is slowly being integrated throughout vBulletin, this shouldn't add too much overhead.

Changed the optimisation settings using my graphics program.

You're welcome...

Thank you dilmah, but I need to know how it's done. Optimizing 3 of em for me is great and all but it doesn't exactly help me as much as telling me would.

THank you all, I'll find something that can do that "Save for Web" thing.

I remember now why I don't bother posting in your threads...

What is that supposed to mean?

If you own photoshop there is an option under File to save for web, instead of saving the normal way. I dont really know much about it, but it does seem to compress the file size down dramatically, probably by decreasing the detail slightly which may not be noticeable in a browser.

Play around with it, it should speed up the laoding of your site.

Fireworks and Photoshop are good, but not free. The Gimp is also good (and free). Install one of these programs, then look through the help files, where they explain how to "optimize" images. Optimization is simply making the filesize as small as possible while keeping visual quality the same or nearly the same.