Yes, it is easy to switch cameras or stop on a particular one. We have two cameras and the scan function switches cameras every 12 seconds (according to manual, and feels about like 12 seconds in real life). If you have video on, then sound and video both switch, if running on batteries and camera turns off, then audio switches every 12 seconds. If you hear suspicious activity (3 year old out of bed again, for example) and want to stay in a room or switch back, you just hit the Ok button (second from top on right side) and you can control what camera). It will switch out of scan mode and go into manual switch mode where the ok button toggles through the available cameras in order and scan mode. You don't have to go into the menus to switch the camera. Hope this helps, let me know if you want me to test anything in particular.
I just bought the camera yesterday, should arrive tomorrow. I have spent a couple of hours looking for extra cameras that would fit this (or even the MBP33 since I think they use the same camera). I don't think that they sell an extra camera at all. Trying to figure out if I should return it and get the Samsung or Summer Baby Touch. We got stuck with a Summer Best View bought in January that they no longer sell second camera for.
If anyone finds second camera, please post it in a product review or on this forum!