Create CSS pin balloons with ease
http://www.jankoatwarpspeed.com/post/2009/04/19/Create-CSS-pin-balloons-with-ease.aspx

Home page of Africa Tour 2008 is a good example of how simple solutions can also be effective. In this tutorial I will recreate (in my own way) their effect using World map. As I said, the effect is more than simple - each continent is marked with a "pin balloon" (I couldn't think of a better name) and when you hover the balloons they get larger. This is something that many of us have done many times, I'm sure of it. However, this example has a trick: balloons grow diagonally starting at the anchor point (anchor point is the little triangle that comes out of the balloon).

Helps you build good looking and functional web sites.