I thought I would take a few minutes and comment on the Jasager project. Unfortunately I haven’t had time to follow what @digininja and the @hak5 community are doing with it, but I have heard some questions about the Fon hardware. It appears Fon has made it extremely hard to get a hold of a Fon 2201 or a Fon 2200, i.e. they have stopped selling them on the online store in favor of the Fon2.0n (which from what I’ve heard, is a fantastic router, but doesn’t support Jasager/Karma and the nice form factor like the old Fons). Enter OpenMesh www.open-mesh.com. They are selling wireless APs hardware identical to the Fon 2100 (AP only, one LAN port). Ubiquiti is another company making APs with compatible hardware. Theirs is called the Bullet www.ubnt.com/bullet, a very slick piece of kit designed for outdoor use. I haven’t had a chance to try out either of these, but have heard from many sources that these are two APs are becoming more popular to run Jasager on. Really the only requirements needed to run Jasager is an Atheros wifi chipset and an MIPS processor. Check out (http://www.hak5.org/forums/index.php?showforum=49) for more discussion on Jasager, Karma on the Fon.
For those looking for a full featured, scriptable and light weight firewall for Windows XP and Sever 2003 (or earlier) check out WinIPFW (http://wipfw.sourceforge.net). While versions on Windows prior to Vista have a built in firewall, it is limiting. The Windows firewall will not filter egress traffic and has poor logging capabilities. Fine grain filtering control of IP address, protocol and port of both ingress and egress traffic are all features of WinIPFW. Advanced logging of any desired traffic is possible as is the ability to create Windows batch script files for automatic configuration.
If you install WinIPFW blocking all in-bound and out-bound traffic you must specifically open ports for web browsing, etc. Also, always install and configure firewalls using a local console to avoid blocking remote administration services (SSH,VNC,RDP).