Engadget have a great tutorial on building your own solid-state AV switcher...
"In this How-To we'll show you how to wire up your own A/V switcher which you can expand and use any way you'd like, for composite, S-Sideo, component, even VGA signals. Sure, you can buy a newer, really expensive TV's with multiple inputs (even component), but for those of us whose credit cards aren't quite up to that challenge, more inputs for less cash would be rather desirable. Let's get started...
