@Charred - I set up a wireless network in my home. The basic concepts are the same as described here, minus the cables. I have the cable modem hooked up to the wireless router, which transmits the signal.
Yes, I do get interference from time to time from other devices, and about once every 6 months I have to reset my modem. I think you have to do this anyway even without the network.
Also, I have to administer the network from a web page. However, you can’t beat the mobility. I can move anywhere I want throughout the house with my laptop, and as you mentioned, it’s convenient when guests bring their laptops over, they can just log on to your network.