Pre-loading images with javascript

It is possible to load images into the page before it opens with javascript, I suggest we get to make a list of images we wish to have inserted into the header so that loading of the forum goes quicker, especially with stuff like:

• Custom buttons
  
• Nav bar images
  
• <th> images ect. ect. ect.

This would dramatically speed up loading time and give us a chance to load more important files earlier...