Another option is to set up your router to only respond to certian MAC addresses. I can control who can access my wireless by accept/deny options on the router.
All the PC/laptops in my house are setup by thier MAC address. Other can see the router but cannot attach. This works for PC's, Laptops, IPOD's, Iphones.. any LAN/WAN device.
Nice thing is, a friend comes over the weekend, you dont have to hand out passwords or security codes. Add the MAC.. when they leave.. either delete it or simply deny it.. then when they come back .. you already have them setup.. just allow it.
Hope this helps...