Icons that when clicked display an overlay?

I’m looking for something that works like this:

The page is a 4×4 grid of icons (boxes with small pictures and a title). When someone clicks on one of them, an overlay gracefully is displayed with more info on that topic. The user then clicks an X in the upper-right corner or whatever to close.

I don’t want a popup in the sense of opening a new web page.

Anyone seen something like this?

Yes this is a standard “lightbox” functionality.

Have a look at some of these items: http://codecanyon.net/search?utf8=%E2%9C%93&term=lightbox