This week's TechMail was DIY pfSense firewall system beats others for features, reliability, and security which takes a look at pfSense which is, in my opinion, one of the best open source firewall systems around. I've used quite a few, and for a long time when I was developing Annvix, used it as a firewall (using shorewall), but pfSense has so much slick awesomeness to it that once I found it and played with it, I've never looked back. I've got a few pfSense firewalls out there for companies I've consulted for and being able to (securely) remotely administrate it, and all the cool add-ons and plugins you can stick in this thing make it absolutely wonderful.
If I get a chance this weekend or next, I plan on installing freeradius on my pfSense box to use it in conjunction with my wireless. Should be a fun thing to do.