The 802.1X protocol for authenticating users and restricting access is starting to hit the big time: This long feature, which I wrote for Mobile Pipeline, walks through how the 802.1X specification works, how it can be secured, and what benefits it is bringing to businesses and academic institutions that want to segregate traffic, control access, and provide a high level of security to their wireless links.
After talking to vendors and customers, it's clear that all the pieces needed to make 802.1X a consistently deployed, secure, successful method of authentication are in place. Even better, 802.1X can secure wired and wireless networks with equal ease, preventing rogue access points, unauthorized Ethernet users, and even sticking virus-infected legitimate users on special VLANs to solve their problems before they hit the LAN.