I want to have a web site which switches the web camera of users, makes a video recording and send results to my web server.
Is it possible to do that? I think it should be. For example such sites as chatroulette.com starts web camera. Should it be done with the Adobe Flash technologies? Is it hard to do that?
the issue with video is that that it has to be encoded to a proper format. To do what you want, you would need access to a flash media server which would handle all the recording/encoding/and saving video from a webcam.
There is also the java based open source RED5 that should be able to do so. But you will need a java enabled webhost to be able to deploy, which is not available with most basic web hosting companies.