Forget about WEP. It doesn't work good, and gets in the way. Set up a real firewall in front of your wireless routers. Allow anyone to get on your wrieless network to see the web, fetch email (POP and IMAP), and send authenticated email. (I don't recall how to do this offhand, and few ISPs support it, but you don't want to allow them to send email unless they have a logged into their ISP.) When you do anything that needs secrutiy settup a VPN to the firewall, or better yet to the other machine.