I'm aquiring a Mac to go with my PC, and both will be editing machines. I want to buy two monitors and have three options:

Mac to both monitors
Mac to left, PC to right
PC to both monitors

I've seen some VGA switchers on ebay. Any thoughts about how to do this right the first time? Will I need to buy more than one switcher?

I have 2 dells that have both DVI and VGA connections, I simply use the front switch button on the monitor to put the machine i want to see on the screen. It does have some limitations (like two keyboards and mice and monitor assignments are not interchangeable), but it is cheap.

You can also get a KVM for each machine/monitor or a higher priced matrix switch. The matrix switch is probably what you really want but they can get pricey in a hurry.