Today I found public-ip. A free hotspot software package.

1 ISO, boot from CD, Linux is started, enter your ID and I run a hotspot with authentication through public-ip.net.
AWESOME, finally I can protect our internet connection from people using my accesspoints without that I know it. (As we test a lot of AccessPoints we do have mainly no encryption active). Due to this my people need to have free access but other departments I want to keep out. WEP, or SSID is than no option.

People from Public-IP.net: Awesome and kewl job you did !