While using the WiFi today at hack.lu I got this pop-up on my N800:
Care to guess what happened? Post a comment!
EDITED TO ADD (21/10): Thomas Roessler managed to capture a lot more than a screenshot while witnessing the attack, read his excellent blog post here.
And be sure to read the comments for my post, several are from hack.lu attendees who lived through the attack.
Didier Stevens 