Linux.com has an article on how to create a secure Linux-based wireless access point.
"Wi-Fi Protected Access version 2 (WPA2) is becoming the de facto standard for securing wireless networks, and a mandatory feature for all new Wi-Fi products certified by the Wi-Fi Alliance. We all know the security weaknesses of its predecessor, WEP; this time they got it right. Here's how to implement the WPA2 protocol on a Linux host and create a secure wireless access point (WAP) for your network."