I don't mean to threadjack, but I have the same issue.
I have a wireless network on WRT54G Linksys router. Ironically, its at the furthermost location from my room. And I like to play video games. I just set up a computer in my room, which is a floor up and about 18 meters away (on a horizontal plane).
I dont have anything on the upstairs computer that'd allow me to access the network.
What do you think would be the best for me to do to get a strong, stable signal for my home network? I'm not very wireless network savvy, so help would be greatly appreciated