QUOTE (azza @ Jul 1 2007, 07:28 PM)

Just took a look at the site, did you realise they are banned by the International Association of Athletic Federations (IAAF) and USA Track and Field (USATF)? I wonder what would happen in Australia if you win a race wearing them?
Last I saw they were
not banned by the IAAF. They're under consideration. The IAAF rules on footwear say that shoes can provide protection and grip but not an unfair mechanical advantage. It's difficult to prove if a shoe is providing a mechanical advantage. I think the USATF rules do specifically outlaw "springs" in shoes.
The
Spira shoe uses a "wave spring". They don't claim a mechanical advantage, just that the shoes return 98% of energy and that the midsoles don't break down. They were the shoe worn in the "World's Fastest 10k" (a downhill course), for 26:01 men's and sub-30 women's times.
One of the big advantages (possibly) would be the recovery from hard sessions the shoes might offer. Especially as they don't lose their cushioning throughout the life of the shoe.
One runner is testing the Stinger Competition racing flat with a view to using the shoes in the London Marathon - see
here.