Well I put in a Linksys 802.11 wireless router to unify my internet connection around the house last month.
Very simple to install and really the best thing since sliced bread for internet and simple file sharing. Good reception even through a large concrete and steel beamed house. Even the smallest of rooms now allow 500K Internet access on the PDA !!!
The utility is good on the desktops, but it is with the portable thingies that WiFi really makes you take notice. It ain't that cheap on the face of it, but prices are coming down fast. It is certainly (in my case at least) cheaper than drilling lots of holes and laying cable. And the Linksys USB Tx/RX boxes are so incrediby simple to install and hook up.
Security is an issue as there seems to be about 5 WiFi networks in range of my system, but we all now have the WEP security enabled and there is no conflict. Two or more separate systems on the same channel causes a stutter, but there are 11 channels to play with so with the limited range, it is easy to find a vacant channel number for your system.
If you are thinking at all about a network - take a look at WiFi - it rocks.
MG