How to load image after page load

I would like my page to load (and show a loading.gif in place of the main not-yet-downloaded image) and then download the main image. Uisng jquery, how can i achieve this? Ideally, i’d also like then to be able to switch that main image using links, again showing a loading.gif prior to display.

I’d also love to know how to do this!

There are ones like colorbox and [url=”]fancybox and shadowbox that you can use.