Power generation from passing metal objects? 1

[CSLufkin]

O.K., I'm not en EE, but I have a question for you guys and I'm sure it goes way back to the basics for you but please bear with me. What would you need to do to generate Electricity from a passing metal object? Similar to the way a linear motor works, but in reverse. I know you can use a linear motor to stop something and turn that energy into heat. How could it be turned into Electricity? Could it be prototyped cheaply and easily?

 

[sreid]

Oh, yes, a steel bicycle frame would be sucked down faster than a trap door in a haunted house.