"I had orthotic made at my chiropractor's office. They were not cycling specific, but I use them in my cycling shoes and like them. I think the term for them is ""rear posted"", which means that they go from the heel to about the ball of the foot. The heel cup and arch area are rigid and it tapers off ot a flexible insole at the front. I suppose cycling specific orthotics are ""front posted"", which are rigid up front and taper off at the back.

At the bike show I saw something interesting: Scandinavian Ski Shop has a system where they take pre-made semi-rigid insoles, heat them and then vacuum-form them to your feet. They are full length insoles and so can't shift around as regular orthotics can. I did not touch them, but they did not look as rigid as conventional orthotics. I think they cost around $45."

When I posted a similar message a couple of months ago, Rich Ramon recommended Peterson Power Beds, available at www.coloradocyclist.com. They took a ride or two to get used to but now I wouldn't leave home without them. Potential problem with any of these devices is that bike shoes (especially Sidis) are sized for fairly thin insoles and almost any orthotic device will use up more than the available space unless your shoes are loose to begin with.