The really "ingenious" solution I've seen in the book: "tinyAVR Microcontroller Projects for the Evil Genius™". Author refers to Elektor magazine, December 2008("LED Top with Special Effects"), (magazine probably would be easier to find in the library)Motion sensor include two coils and OPA's, that sense Earth magnetic field. It allows to get speed, direction of rotation, plus synchronize leds for POV effects. Last feature is impossible to obtain with accelerometers or force sensors.I'm not sure why hall effect sensors were not used in design?
Author refers to Elektor magazine, December 2008 ("LED Top with Special Effects").