I haven’t written about using alternate software on certain types of Linux kit before but its a very interesting way to play around with embedded Linux and also to massively extend the functionality of relatively cheap equipment for nothing.
We use a basic router the wrt54G running an alternate firmware as our wifi AP using dd-wrt gives you extended router functionality that you would normally have to spend quite a bit more to get on semi pro or second hand Cisco kit. You can do exotic things like run a wrt54g as a kismet drone and use it as part of a IDS system for wifi.
One interesting thing that came out of my Cisco wireless course is that the antennas from Linksys also fit some of the Cisco Aironet range as they use the same connectors.
You can also extend a cheap NAS (NSLU2) that Linksys and run a full Linux distribution on a £50 quid piece of equipment which allows you to have a very small fully featured Linux system useful for running home networks you can run a central itunes servers for a house and people have even physically hacked them to provide extra ports add internal wifi cards etc. some people even considered using NSLU2’s to act as controllers for some amateur high altitude experiments (though I think they have switched to the even smaller Gumstix now)
I have just ordered a NSLU2 to play around with and also to give me a small Linux system at home for use as a central backup server for the computers in the house.
More later when it arrives.