efficient preload of large number of images

I've got a web application which has a lot (107) of (small) images. These are basically used to set up a GUI theme (like rounded button corners, a specific look/fee) and to display object status. I tried to preload them by putting them initially in a hidden div up front before they might ever be used. But each image seems to initiate a separate http request. Is there any way to get the images to be preloaded in bulk with fewer requests?

Try searching postload in the javascript forum, might not be exactly what you need but it won't delay loading of the entire page.

With this quantity of images it may be an acceptable solution.