i just installed a linksys usb adapter and it works fine. you just plug it in and when it prompts you to, you insert in the cd. i now shows up as a wireless network usb adapter in device manager. then just use windows explorer to enter your ssid and wep/wpa key. it automatically started to scan for me and i just had to enter me wep key. the exact model im using is a linksys WUSB54G .
i can get my routers signal, which is upstairs and i get a very good connection level, usually around four bars. the speed varies, but it usually stays around 36-54 mbps. i can also pick up some signals from around my house, but they are not that strong. here's what it looks like:
