Router firmware replacements and building wireless routers

• LinksysInfo, WRTrouters and the Wikipedia WRT54G entry contain a wealth of information about the Linksys WRT54G series wireless routers as well as other models.
• Popular alternate firmware distributions for the WRT54G include OpenWRT and DD-WRT.
• Tomato Firmware and the fork TomatoUSB,which supports 802.11 N hardware, are excellent choices for firmware replacements as the user interface is greatly improved over the stock firmware.
• Sveasoft combines the GPLed WRT54G firmware with some proprietary patches to produce a commercial version of the firmware replacement.
• Hacking Your Linux-Based Wireless Router article from ExtremeTech.
• A number of mobile routers allow users to share a cellular modem PC Card connection. These include Junxion Box which works with work with GPRS, EDGE and EVDO over either Ethernet or Wifi. The Kyocera KR1 Mobile Router (also sold as D-Link DI-725) works with EVDO and USB handsets. The Linksys WRT54G3G supports 3G/UMTS connections via a PCMCIA/Cardbus interface.
• StompBox has instructions for building your own mobile 3G/WiFi router.