SpeakUP.cf allows you to create instant videoconference for up to 4 people. It uses peer-2-peer connection between clients to transmit audio/video (WebRTC protocol).
While client is still in early development, there are no binaries/installers available to download. Client is built using Visual Studio 2012 Express.
If you are going to build your own version of client, you have to choose either x86 or x64 configuration in Configuration Manager (CefSharp is unable to work with option "Any CPU").