As a follow-up to my post below about a Real Router for $60, word comes that recent models of the popular Linksys WRT54G can now be converted to Linux like the older models.
The current, series 5 models of the WRT54G have come from Linksys with the VxWorks OS loaded, and were resistant to being flashed with alternate firmware. But...
Jeremy Collake, aka "db90h," appears to have created a "VxWorks Killer" flash image that overwrites the VxWorks bootloader on series 5 WRT54G routers with normal Broadcom CFE firmware. This then enables the device to be put into maintenance mode at startup, after which Linux firmware can be installed easily.
[via Linux Devices]