Locking the screen orientation on your device.

Many people have asked for a screen orientation lock feature in Live Cams. We have not bothered with this because Apple has added a built-in feature to OS 4.2. When running any app, simply double-tap the home button on your device to get the task switcher bar to appear at the bottom of the screen.
Swipe left to get to the iPod controls and you'll see that there is an icon with an arrow on it. Toggle this to lock your device in or out of the current orientation.

Here is a tutorial on how to do this, along with a description of the iPad lock switch on iOS 4.3:

http://osxdaily.com/2010/12/03/how-to-lock-ipad-orientation-in-ios-4-2/

Because of the technique, this works while you are running Live Cams. If you are watching the thumbnail screen or full screen video and want to stay in landscape mode, just hold the device on its side and follow the instructions above.