Pop-up upon mouseover of name, with details about that person

Idea: when in the indexes (or everywhere in fact) when one mouseovers a person's name, have a balloon pop-up with some details about that person, just like Facebook does.

No reason to have other users need an extra click just to see details about that person.

The details could be those that are currently found in the right sidebar next to one of their posts, for starters.