NYCwireless used to maintain a list of thier meeting presentatsions
However it seems as if it's no longer available. These are the ones I've given.
802.11n From the February 28th, 2007 Meeting by Brian Walden. PDF
From Analog RF to HDTV and Wifi From the May 25th, 2005 Meeting by Brian Walden. PDF and video samples
Safely use untrusted access points From the October 27th, 2004 Meeting by Brian Walden. PDF and full software list
4DI's Defcon Wireless Shootout Wins From the August 27th, 2003 Meeting. Brian Walden as part of 4DI talked about the equipment and technqiues (or lack thereof) to win 2 different categories at the Defcon '03 Wireless Shootout. Presentation PDF and a TechTV segment on the Defcon '03 Wireless Shootout. Also part of 4DI is Terry Schmidt and Ben Serebin.
Wireless WAN - ICE Networks (Details of an ISP in Puerto Rico) From the April 24th, 2002 Meeting by Brian Walden PDF File