[jrnkntl]

afaik (and from my own experience) that won't work.

  "As long as the universally supported WPA encryption protocol is used,
  each individual user receives their own private “session key” that absolutely 
  prevents eavesdropping between users, even through they are all using the
  same WiFi password."

from: http://steve.grc.com/2010/10/28/instant-hotspot-protection-f...

[docgnome]

Yeah, we tested it on our WPA encrypted wireless and didn't get anything. It was seen when I logged into facebook but my coworker wasn't able to login as me. At least not with Firesheep.