trying to find a javascript dropdown control

I'm looking for a dropdown similar to the openid site-select dropdown on the stackoverflow login page:

... and for now I'd rather not sit down and write one myself. I'm looking for one written for inclusion in plain html/javascript (php code), must be free for commercial use.

From stackoverflow

• There are dozens of jquery plugins that you may find commercial worthy.

  Alterlife : Is jquery usable with plain html / php?

  George Stocker : JQuery is a JavaScript library. So I'd say 'yes'.