Use the Nintendo Wi-Fi USB connector. It's actually in Nintendo DS packaging and is probably located near the other DS accessories at most stores. I picked mine up today from Circuit City (during my fruitless quest for a nunchuk) for $35 and it works really well. It is about the size of a jump drive and just plugs right in back of a Windows XP computer in an open USB port, has great range, and even works despite being on the other side of a room full of furniture, underneath a table in the corner. I'm pretty sure it only works if you have a broadband connection on your computer. The only problem is that my Norton Firewall doesn't like it, but there are help pages on nintendo.com and it works great when the firewall is turned off.