Make it the default

It has only been since wireless router vendors (or is it the broadband suppliers) have supplied equipment with WEP set up out of the box that most home networks have been protected at all. Most consumers can't be bothered to set up security - so save them the hassle with out-the-box WPA with a nice big key and a decent quick-start poster on linking your existing machines to it.

A tip: Set up the IPs statically and leave the DHCP switced on, only ban all addresses the DHCP will provide. Couple this with WPA and MAC address filtering and it might take up to half an hour for the hacker to get in :)