>Just out of curiousity, what's an example of when you would want to do something like this? Where an operation would be performed based on a select value of the combo box, before the user okayed the value. Especially on a web page. It would drive me batty if the browser updated if I clicked my mouse wrong.

I see it on tons of pages, like, where you pick a region or language to view the site from or in.

Why do they do that? The same reason they do use all the other horrible Web UIs, cause they can and they don't know better.