I had to move my office to a new room in the house that does not have a wired ethernet connection. Since running wires in our 100 yr-old house is painful, I went looking for a wireless solution. One of my chief drivers is 'not' spending money. I have a Linksys WRT54GS that I could make use of. I've been toying with the idea of using a DD-WRT (cache) firmware in this router, but never had a real need - until now.
DD-WRT is a 3rd party firmware for the WRT-series routers and is support, among other things, Wireless Client Bridging. Following these instructions at the DD-wrt wiki (cache), I was able to bridge my wired connection in the wRT54GS to my wireless FIOS network.
One item of note - I was unable to make the bridge work with WPA2 encryption on my Actiontec router. I had to back off to WPA encyption.