Show WX pico projector used to create an open-source spherical display
Nirav Patel developed his own spherical display - that costs about $200. The idea is to use a pico-projector (he used Microvision's Show WX, a laser projector is required as it's always in focus), a 8" frosted glass lamp globe, a fish lens, a tripod and some software (which he nicely made available as open source). You can see it all in action here:
Interestingly, the brackets that are used to attach the globe to the projector/lens mount are 3D printed, and the design is available as well.