Zap aiptasia dead with laser beams! (updated with new videos)
Reef2Reef member CalmSeaQuest has started a thread aiming to become the definitive reference for "best practices for the use of lasers in aquaria." In his thread, CalmSeaQuest describes how he uses a Class IV 1800mW 445nm (blue) laser to kill a wide range of reef pests: Aiptasia, cyanobacteria, valonia, bryposis, vermetid snails, predatory crabs, and overgrown Xenia and GSP. In essence, these powerful handheld lasers will rapidly fry/boil virtually anything.
While highly effective at eradicating whatever you target, the use of these lasers is (unsurprisingly) extremely dangerous and must be operated with utmost respect and care. Class IV lasers will quickly cut through cardboard and will instantly blind people and kill corals and fish with mere incidental contact. Looking at the beam from any angle may also cause eye damage, including those of your fish. In his thread, CalmSeaQuest has begun work on establishing safety protocols for anyone looking to try lasers in their reef tanks.
With the high price and inherent dangers of high-output lasers (and possible legality issues), the use of lasers is unlikely to become a mainstream method to control reef pests. Advanced Aquarist does NOT recommend this practice. Still, we can't help but applaud the responsible and intelligent hobbyists pushing the frontiers of high tech reef techniques.
Here is a video by CreatiVe2 showing the use of laser to zap aiptasia. CreatiVe2 also participates in the Reef2reef thread.
UPDATE: New videos of lasers in action posted at Reef2Reef