Well, for starters, when you have a computer hooked up to your home theater, you need a keyboard and a mouse to control it. It's not always possible to take the one from the office to accomplish this. Also, usual keyboards are pretty big and cumbersome. Sometimes you just need something small to type in some commands. Finally, not all keyboards and mice look good when they are on the coffee table. In fact most just look bad. It's best to have them tucked away. The best way to accomplish this is to have a small keyboard, something with a small form factor that's unobtrusive.
We found that the Tiny Wireless keyboard is a full package. It's wireless, has a small footprint so that it won't get in the way, it has 78 keys plus an additional 20 media keys and an integrated trackball mouse. This means that you won't need an extra mouse, it's all integrated into one sleek and compact device. It operates on 2 AAA batteries up to 30 feet away. The Tiny Wireless keyboard is available from Brando for $50.