At DefCon a new packet injection tool for wifi was brought to attention.
The tool is called AirPwn and a beta download is available here on Souceforge.
The devolpers have a small demonstration including images and videos.
It only works on 802.11b networks at this time.
Kind of amusing, the actual test the did was the mage replacement mode using goatse and capturing peoples reactions. Take a look at the pics of victims!