In order to use the Wi-Fi feature on the DS or the Wii. You must have atleast Broadband internet. I have Broadband, and have a Router that is both Wireless, and wired. Like many have said, it's about $50 for the Router. Then all you need to do is link up the DS to the Router. I'd suggest you put a password on the Router's wireless access. When it's setup up, you won't have to keep putting in the password. It will be saved on your DS system. The Nintendo Wii is pretty much the same as far as setup goes. I know you didn't mention having the Wii, but thought i'd toss that in just incase you get one. I haven't played any games via internet yet, but nice to know it's available. Setting up the link is really easy. If you have questions, Nintendo has a section on there site that will help you through the link up. Oh, and about the firewall. Firewall's block a lot of access to and from your pc. And if it's not set to allow the DS access in or out of the net. You can't play anyone online. Really don't need to turn it off, but just allow the DS access. Not sure if it will block access, as i didn't change anything on mine. And the connection was fine.