Recent advances in the miniaturization of green laser diodes from companies such as OSRAM have made possible miniature laser projection systems from a company named MicroVision. I have used a SHOWWX laser projector from MicroVision to project games like Tempest on the living room wall. It's fun to play with a giant image of a classic arcade game. The SHOWWX laser projector is about the size of a cell phone and uses the older green laser technology where an infrared laser is beamed through a nonlinear optical crystal to produce green light and then bounced off a tiny moving mirror. The new green laser diodes are smaller and would make possible an even smaller laser projector. MicroVision also has the technology to project lasers with different polarizations so that you can wear polarized glasses and view images in 3D like in some movie theaters, but this technology has not yet been commercialized. It would be nice to have a laser projector in a future handheld computer.