I made this prop to wear to the Iron Man 3 release (and to test out some new technology for a future project).
The whole thing was designed in OpenSCAD and 3D printed in ABS (both the housing and the diffusor puck). A Teensy 2 module drives the LED strip (WS2812 clone, 60 pixels/m) and is is wired up to a BLE112 module for communications.
You can control it via Bluetooth (no app yet, you hand craft a 1, 3, 6, or 7 byte message in a BLE explorer app to set a greyscale color, or one/two RGB colors and a ping-pong speed). By default it boots up into ‘Arc reactor blue’ with a soft breathing animation.