How do I add persistent tooltips that have to be dismissed?

I’ve been trying to find an example of what I mean to back up this question, but I’d like to show a balloon tooltip hovering near certain items on my new WP Blog (hosted on my own server) that shows without being moused over, and has to be clicked to be dismissed. Kind of like the custom tooltips on Ebuyer but showing by default?

Also, why is the ‘details’ box when you ask a question on here so ridiculously small? It’s only 2 lines tall in FF3!