the content of the facebook-dashboard is loaded asynchronously e.g. friends, messages and groups.
Lets drop the facebook example. I know what I suggested is possible because I have seen it and read an article about it. I just can't remember where.
I will look into jQuery. Surely there will be enough content about it.
I will keep you in the loop about my findings and if I am up for the task of implementing it for 3.0.6 or maybe even earlier.
One more question about jQuery. Is the included .js-file untouched? I would like to use the google hosted jquery library because I like me some cdn power where ever I can ;_)