It makes sense on paper, but I'd be interested to see actual benchmarks, just to see how much of a speed boost you get with this method. I certainly didn't notice it on my machine (tested against the jQuery UI Autocomplete)

I chuckled after reading the article at the somewhat misleading title. I was assuming it was pure CSS, no JS...and was wondering how the CSS was firing events! :)

This is still pretty neat, IMO, and I like how it emphasizes the "markup as your data model" concept.

This can be made to work in IE8 using two selectors instead of one. See Kbenson's solution.