Bubble-based relationship maps

[djo26]

Hi everyone, do you know if there is a good javascript library to create a "bubble relationship map"?  It's the same idea as this:
http://blog.linkedin.com/2011/01/24/linkedin-inmaps/

I want to be able to click on a "bubble" and then that bubble becomes centered on the screen with branches off to the entities that relate to that bubble.  Then you can click on the other entities to center them and bring up their relationships.

Thanks!