This How-To provides step-by-step instructions for creating a Universal Wireless Repeater appliance: a device that you can place anywhere and it will wirelessly repeat the strongest signal, onto another wireless network (with or without security). This functionality is also known as Wireless Client Bridge, or Range Expander. Unlike WDS, once you have this appliance setup, it will work with any open network.

[ Universal Wireless Repeater - DD-WRT Wiki ]

Since the FiOS router they give you does the WiFi for you, I can flash my old Linksys and turn it into a repeater to help get the signal upstairs to my wife's PC. Just have to figure out where I packed it first...

Update: the Linksys that I had would only allow for the "micro" version that can't be a repeater. However, I was able to set it up as a Wireless Bridge which allows it to replace the WiFi dongle that Yaty had been using. Since you can boost the signal of the Linksys, it can much more easily reach the FiOS router and she reports that the speed is much improved. Once again, thank you Linux.