All projectors designed primarily for business use are "PC Friendly." That is they use a standard resolution such as 1024x768 which all video cards support. Even some projectors with higher resolutions, such as D-ILA machines, can be use with "pixel perfection" by adjusting the output of the video card with a program such as PowerStrip.
Some projectors, such as the Sony VW10HT, have 16:9 display panels. They are not considered "PC Friendly" because, even if you adjust the video card output to match the pixel count in the horizontal and vertical dimensions, the projector will not directly sync to it, or it will assume a nearby input resolution such as 1280x720, which is a standard HDTV resolution. With these projectors you have to jump through some hoops to "trick" the projector into accepting the PC output at its native rate.
Supposedly the newer 11HT version of the Sony works better with PC's.
I don't think anyone has tested the new generation of 16:9 DLP projectors from Sharp, Seleco and Dwin for their PC friendliness. This is one of the things I'm hoping to hear from outside reviewers.