[Colonel Flagg]

It's the LZR suit from Speedo, and yes, they are more than happy to supply it to anyone who wants it. The only people complaining about performance enhancement clothing are the other swimsuit manufacturers, and of course, those teams that are contractually obligated to wear suits of different manufacture.

It's a pretty fine line. I seem to remember there was a type of pole that was deemed illegal for pole vaulting - I think it had better shape memory or something, which gave it better snap at the same weight. However, in this case there was independent testing conducted by labs reporting to the Swimming Committee (I don't know the official name) that showed that the advantage was statistically non-meaningful.

And there is, of course, the Placebo Effect - if you believe the suit gives you an advantage, then you perform as if it does.