If you get a Linksys WRT54G and apply a third party firmware like Sveasoft's, you can turn the router into an access point. That should send the signal out to the rest of your place.
I've tried LInksys's repeater. It has terrible instructions, makes no sense when you're setting it up, and will drive you mad trying to get it to work. I got it to work, even though the lights on the unit claimed it wasn't working, and I have no idea what I did. Fortunately, this was for someone else who I did not particularly want to speak with again, so it all worked out
The best thing about the WRT54G plan is that when you move and get your own service, you can turn the thing back into a router and use it normally.
[The WRT54GS will also work, just in case you search for the normal one and find that nobody carries it anymore]