Ubuntu Multimedia :: How To Create Video Chat App

I have been tasked with the job of finding a way to create a video chat application on Linux to use with our health software. We are basically just wanting to add a video / audio component to the system. I have been using Ubuntu a long time and have decided to use it as our platform for the new software. We currently use Emblaze VCON with our software on Windows and I want to eliminate the need for Windows completely. We supply the hardware so if I can get good quality video chat integrated into our software then I am all set.

I have been playing with some apps like vlc, cheese and luvcview. I am quite impressed with the video quality I am getting so I know Linux can give our users a great chat experience. I even tried Skype 2.0 beta and that worked great too.

I see the software working just like Yahoo or MSN does. I provide a list of users and whether they are online and when you double click on their name they get a ring and prompt to accept the incoming call from "Joe". If there is an engine already in place that we are free to use and bundle with our paid product then that would be great. I am really ignorant on GPL licensing so I want to be careful on what we do. Also, I think this method is best for the connection... I like the idea of a server which receives input from all clients and tracks their online status but when you make a call to the other person it communicates p2p style to minimize hops and server load. We will be controlling the firewalls on the hardware but not what this hardware may be behind, ie. Router - so I guess I need something that can tunnel through / around such obstacles.

I would really appreciate if someone could point me in the right direction on what I could use to do this and also not have to worry about licensing and Intellectual property violations. Btw, I don't see the need to modify the software if it can handle the p2p chat out of box and do it well. I will write the components to handle online / offline status if the "engine" doesn't handle this.