You can buy a Linksys Wireless adapter for the Xbox (works with all systems ps2, xbox etc) and get a wireless router for $30 avg anywhere. That will be the best option. or just buy a really long Ethernet cable and run it across the room from the modem to the xbox just when you use it. i just did a complete wirless network in my house, Vonage, Tivo, PS3, Xbox360, 2 Macs and a dell all on G band wireless. Soo easy and NO WIRES. Love it!
iPhone 3G 8GB, iPod mini 4gb, iPod nano 2gb
Powermac G5 Dual 2.3Ghz, 2gb Ram, 250gb hdd
MACBOOK 1.83ghz, 2gb ram, 320gb hdd
Mac Mini G4, 1.42ghz 80gb, AP/BT (SOLD)