I bought a component switch with 2 outputs many years ago but It doesn't look like anyone makes these any more. Monoprice carries component splitters but I've never used them so I can't tell you if they would degrade your video signal.
There's a very inelegant way of switching where you output your signal to. You could attach a component coupler to the component cable coming out of your Xbox. Run component cables from your TV and your projector and hook them up according to which display you want to use. It's a pain but it works.