I've been working on an interesting idea for adaptive optics. Sony Minidiscs work on an unusual property of magnetised reflective surfaces. If a spot on the disc is not magnetised a laser will reflect off it normally, but if magnetised it will reflect at a different angle.

So it may be possible to put small magnets behind the mirror of a reflecting telescope and alter the reflection angle like in adaptive optics. This would be much faster than deforming the mirror.

The defelection is enough in a minidisc to make the beam miss a deflector so the change of angle must be substantial, probably more than necessary for adaptive optics.