I don't own one of these. I now own a Denon 5800, which can handle HDTV component switching. Before I purchased the Denon I was going to go the external switch rounte using this Belkin switch.
In a multicomputer setup, the other ports are for keyboard and mouse to each of the other computers. When using this as a VGA component switch, you just hook up the vga connectors and disregard the others. You'll need a breakout cable for each source and one to go to the projector.
If you get one, let us know how it works out.