What is the best free videoconferencing software?

I have to come up with a cheap video conferencing solution for my work. We already have cameras and mics. I just need to find some software that allows more than 2 users to be talking to each other at the same time. I have found alot of good software out there but it is a paid service. Also applications such as skype would be ideal but they only allow 2 people to talk to each other. So if anyone knows of any software that’s similar to skype or windows messenger, that allows 3 or more people to talk, it would be a great help!

Oovoo is what your looking for.

www.oovoo.com

Pseudo-3D Video Conferencing with a Generic Webcam (Chris Harrison, Scott Hudson) – ISM ’08

Warpia ConnectHD Video Conferencing Camera – USB 2.0 $194.49 Warpia ConnectHD Video Conferencing Camera – USB 2.0