Very simply put, I can control my X10 devices at home from my iPhone, including my Cameras, and watch my cameras on my iPhone as well, all while being away from home. I've seen a few links that mentioned Mellowares X10 Commander, which I use to control the devices. I also use Orb's OrbLive product to stream all my media, including my WebCam configuration. Using the X10 VA11 Video to USB convertor, the Orb recognizes it as a connected Web Cam to the computer. All my cameras are setup in X10 Commander as a seperate controlable device.
To use, I go into X10 Commander and select a camera, turn it on.
Then I exit X10 Commander and to into Orb, select Video, WebCams, then the selection for the VA11 cam and see the stream from the camera I turned on. To change cameras I have to exist Orb and repeat the above process (including turning off the previous cam first).
Yes, it's a bit cumbersome, but I don't mind since I have full control and access to viewing my cameras from my iPhone.