Here is a device that lets you present or project videos on your walls easily. The Lighty is a robotic laser projector with voice recognition. It rotates, tilts, and self-adjusts to serve you. You can control it with a Leap Motion controller as well.
The device has a battery powerful enough for 5 hours of video or 10 hours of internet radio. It features WiFi and Bluetooth connectivity. More information is available here.