Tony, nice little tut on wireless security. I have just a few suggestions though:
Even easier than WPA is WPA-PSK(Protected Storage Key). Setting up WPA-PSK is as simple as deciding on a passphrase and the rest is rather simple. I set mine up in probably about 10 minutes tops. I'm not entirely sure as to the availability of WPA-PSK in all Windows OS's though.
I know of at least a few Linksys wireless routers offer WPA-PSK. The only problem I had was setting up some versions of laptops I connected to the network (running XP) because the WPA-PSK option wasn't available in the wireless setup dialogue box. I had to go to MS's site and download this patch on a couple occasions. Again, I don't know what OS's can use WPA-PSK as I'm mainly familiar with/use XP on the wireless network.
Next thing is that I like to limit my IP range that the DHCP can hand out. I have only enough IP's to cover the computers connected to my network. There's no reason for me to allow my wireless router to hand out 100 IP's when I have less than 10 computers on my network.
Also, like chsh said, enabling MAC filtering is a key element in keeping people out of your wireless network. Granted anyone can spoof a MAC, but add MAC filtering along with other security measures and you can really fortifty your wireless network.
In any event, that's my thoughts. Nice article though.