There's a reason that free energy cranks are regarded as cranks - they are.
They always seem to involve magnets these days - as Tim so rightly points out in order to benefit from the energy in one you have to do work against it in the first place.
It may help if you try thinking of it as a portable hill you have to push against it to get the energy out.
As to steorn - well lets have a look:
http://news.bbc.co.uk/1/hi/6283374.stm
Goodness me a technical defect stopped it running as a perpetual demonstration - imagine my surprise!
If you run a spinning gyroscope in magnetic beaings it can run for a very very long time because the e nergy in it is conserved. The small amount lost can be topper up by a battery.
As soon as you try to get usable energy out it simply stops because no energy is being created.
Scam or self delusion - I don't know - I do know that a fool and his money are soon parted