[cisco-voip] Open a door by using a Cisco ip phone

[cisco at ip-project.com]

Hey all,
we would like to press a button on a 79xx phone to initiate a door opener. I've searched, but only found one commercial application (ANDtek) with no technical details. How do I connect the door opener? Do I need a PC with a serial port? Or is it some kind of analog phone with that functionality connected through an ATA? And what piece of software do I need? 
And second, connecting any kind of webcam or surveillance cam to the network and watching the output on a 797x would be fine. Again, what cameras do I need, and what piece of software?

Any links? 

Thanks,
Hans-Peter