Awhile ago I purchased this Linksys WRT54G wireless-g router. I got it to replace a Netgear wireless-b router that didn't play real well with the Proxim card in Patty's laptop. This Linksys router is a great little box. Recently, I gave my neighbor's iBook access to my network (I'm sorry, dialup just makes me puke). He got hooked on high-speed internet access, even if it was only available on one side of his house. Eventually he wanted to get his iMac and Tivo on the network, too. The obvious option would have been to purchase wireless devices for both boxes. Unfortunately the placement of these devices was not conducive to communicating with my little WRT. So we decided to have a little geeky fun. He purchased a WRT of his own and we got to work. First step we took was to flash a third-party firmware on both WRT's. We chose HyperWRT since it stays very close to the original Linksys codebase (read: stable operation) and opens up *just* enough of the hidden feature-set of the Linksys firmware to make it useful for us. In our situation, we wanted to explore WDS (Wireless Distribution System). In layman's terms, this would allow our two WRT's to form a huge wireless cloud around both of our houses that appeared to be one Access Point to any of our clients (laptops, tivos, etc.). So any device connected by wire or wirelessly to the WRT in his house would send packets through his WRT which would then forward them over a wireless connection to my WRT and eventually to my Linux router out to the big, bad internet. This extended the wireless cloud of the network and allowed him to connect his iMac and Tivo with regular ethernet, ensuring a cheaper more reliable network connection. Here's an awesome guide on using HyperWRT+WDS:
HowTo: Configure HyperWRT 2.1b1 with WDS - LinksysOnline.com
One caveat: If you use HyperWRT for WDS, you have to stick with WEP encryption. Others have reported very spotty connections trying to use the more robust WPA/WDS combination with HyperWRT. If you're set on using WPA, you might want to look into Sveasoft's Alchemy firmware for the WRT. I've heard dubious reports on the stability of the Alchemy firmware, though, so YMMV.
UPDATE: The LinksysOnline.com link is dead (Thanks, A!). Here's a link to the content of that page via the Internet Archive's Wayback Machine.
wds, linksys, wrt54g, wireless