Re: Steorn?
It's a scam. It works but eventually you need to re-Gauss the magnets. This takes more energy than is output. Such devices have already been patented, operate well within the laws of thermodynamics and are certainly not overunity generators.
Some good comments on although it does get hijacked by an Iranian madman half way through.
The main hint is that they themselves keep thinking and talking so small. If you have a genuine overunity generator (400% they claim) why would you be talking about long life batteries - why not power the entire national grid? The "zero point energy" scam, as it was called in its previous incarnation, simply does not scale.