You can now flash your WRT54G V.5 and V.6 routers with linux. This replaces VXworks on the router.
http://www.bitsum.com/openwiking/owbase/ow.asp?WRT54G5%5FCFE
It’s been out for a few weeks so it should be very reliable.
At www.linksysinfo.org there is an excellent article about how to fix your bricked WRT54G router. There are several different methods that they discuss. I tried it on several routers and it worked. Good luck.
There is a very good chart on www.linksysinfo.org that shows the differences in various firmware hacks for the WRT54G series routers.
The chart compares Sveasofts Alchemy, DD-WRT and Sveasofts Talisman. There are several versions of the routers that have been created and this which ones are compatible with which firmwares.