AOL Software Engineer, Greg, has released a freeware skin/theme creator tool for AOL Instant Messenger 6.1 called AIMThemer. This application allows you to change the colors of various parts of the AIM software, artwork for the top left hand corner of the buddy list, as well as the image (in a png format) that represents your theme in the color chooser.

Download here

(Note: Requires Microsoft .NET framework 1.1)