I had an old WRT54G v2, it has been running old sveasoft code for over a half decade, doing it well at that. I wanted something better that would work on that platform, and hesitant until now, I've found it. OpenWRT offers hundreds of packages which can be installed just like a package on any other Linux OS giving it an immense amount of flexibility. Using X-WRT I've also given it a great interface which I can view nice RRD graphs [like m0n0wall & pfsense], and quite a few other nice features.

The thing about OpenWRT is, that to me at least, it's targeted to the hardcore enthusiast, in many ways at that. Installation couldn't be easier. Configuring it post-install is another story, but that's where people can get fouled up, but give it time, and it will become the most perfect painters pallet for your networking needs.

Tricks to get you going:

dropbear is the default ssh client, access it using:
      #ssh root@192.168.1.1

Once you ssh in, update your package list:
      #opkg update

At the moment there are a few bugs/issues with my setup using Kamikaze 8.09, if I try and ssh in and use multiple instances of the web interface, it will just freeze up. If I do one or the other fine. I think it's more of a resource issue that causes a problem.

Be careful, deprecated how-to's etc are more than abundant. If at first you don't succeed, google your ass off :D.