Blu-Ray Waterproof Laser

The blu-ray laser is waterproof and packs quite a punch. At 182 mW there is enough power here to pop dark colored balloons (see the video after the break). To make this happen, he found an LED flashlight that has rubber o-rings for waterproofing. Although small, there is enough space in the case to house the battery, driver, and laser diode. A thick ring of aluminum is placed around the laser diode to act as heat sink.

[Source] Hack-a-Day via Laser Pointer Forums