Thomas uses Skype a lot and it drives him nuts that the video will suddenly go into widescreen, and the audio degrades in quality. Leo says that's by design as Skype will see how much bandwidth he has and then adjust the video accordingly, even if it degrades the audio. Leo says he can get a program called WebCam Settings in the Mac App Store which will give him more control. It's about $8. But it may not overrule Skype.
If he had a Windows machine, there's an app by NodeWave called Force Skype HD Video. If he buys his own webcam, rather than using the webcam on the computer, he may have better control of what's going on with his video image. Leo suggests looking at the Cisco Precision HD camera, but it isn't cheap.