Dicovering rogue access points

From what I hear all you need is a wireless nic, a laptop, and an empty can of pringles potatoes chips. See below

http://online.securityfocus.com/news/899

Retrieve the logs from your DHCP server. This is a very rich source of MAC addresses seen on your network. Identify the OUI codes (first 24 bits) associated with the wired network cards used in the network using http://standards.ieee.org/regauth/oui/index.shtml
All others are suspicious and could be unauthorized wired devices, authorized wired devices with MAC address spoofing software (macof...), or unauthorized wireless devices with or without spoofing software (Wellenreiter...)