There are preliminary Xbox emulators, but their game support is extremely limited. I think the only playable games are Halo and Turok.
The device I was talking about is the X2VGA+:http://www.x2vga.com/
What sets it apart from other devices is that it takes the HDTV inputs and displays them on a CRT. The downside of this is that it does not work with games that do not support HDTV res (480p or higher), but so few games only support low-res 480i.
According to this list, about 90% to 95% of games seem to support HDTV:http://www.hdtvarcade.com/xboxlist.htm