Ask HN: Successful startup publicity stunts?

Loved reading about the wepay's publicity stunt with the icecube, as well as paypal's stunt with the t-shirts. (http://www.wepay.com/blog/)

Airbnb's "Obama O's" episode doesn't quite fit into the same category, but is still very cool so worth mentioning!

Can anyone remember any other successful publicity stunts that startups have pulled???

Dave