This might help you get started:
http://www.dynamicdrive.com/dynamici...ockcontent.htm
The script lets you use an image file, not just text or hyperlinks. So you should be able to adapt the code for what you're looking for. The flamingo image is set to move dynamically for a set time, then take roost back in position (so to speak). But you can customize the script to make that dynamic docking feature permanent.