I have an Optoma Pico project (purchased here). It’s really neat as a super-portable solution, but of course it’s not as bright as a full sized unit. On the other hand, you can easily carry the project in a pocket or, more importantly, a small briefcase.
It will be cool when pico projectors become standard on cell phones. That will eliminate the tablet and laptop market in one week. Until then these things are about as useful as sought after as zip drives were… just a device waiting for its place in the world.