Look at what I found while crawling around.

http://www.safalra.com/web-design/javascript/mac-style-dock/

Very unresponsive... but not too bad for an inbrowser app?

I've seen a couple of these web based docks, but this one by far is one of the best. Its pretty responsive for me albeit some minor things.

Very interesting, I could probably implement this javascript in my portfolio site.