heres a video of it in action.
Step 1: Parts or Uh Stuff You Need
Plasma mug: uhh i think its discontinued
Curiously Strong Magnets: http://www.thinkgeek.com/geektoys/science/770f/
get the larger sized magnets ( i used my own magnet it was stronger)
An altiods tin : can't get it from Think Geek
Step 2: Assembly
Put the tin on top of the mug
put the mug on the coster
turn it on
Step 3: WHATS WRONG WITH IT?
Sorry i can't scan a picture while its running and i have no camera.
Step 4: Fun Time!
1) put your finger on the side of the glass, it will stop spinning. moving your finger up and down will allow you to adjust it and start it up again at a slower rate.
2) Put your finger on the altoids tin, it stops spinning right?
3) Slow it down, to do this lift the tin upward slowing notice how it slows down and ultimately stops.