There are a handful of websites that push the edge on rich ad units: the New York Times, Gizmodo, Yahoo and ESPN (to name a few). There are also a handful of brands that create great rich ad units... Apple is clearly one of them. For instance, Apple has taken over ESPN and Yahoo to promote iPhone gaming.
Apple and ESPN teamed up once again - but this time to promote the iPod Nano... its a tie to the television campaign that is currently running - but it is also the first time I have seen a major online campaign for the Nano (particularly when the iPhone and iPod Touch are so hot / important).
The movement in the ad expands beyond the unit's traditional size (which is already quite big) and the Nano / dancers move fluidly into ESPN's header. It is quite attractive and, any time large / slick movement occurs, it is certainly eye-popping.
Also notable: large ads like this can load slowly and cause usability issues - this was done quite well and usability was not affected. In fact, the ad (and it's noise and movement) can be easily avoided.