I think orthotics are way over prescribed. I used to wear them. They were completely rigid. I developed horrible PF. It has taken a LONG time to get over things but I'm through the issues now. I am totally out of my orthotics and when at home - in a home that is 90% hardwood floors - I'm barefoot 100% of the time. I think they really ended up messing up my feet (making them very weak) as well as my calves. (Making them very tight and atrophied due to non-use.)
I wrote a blog posting on my perspecctive on orhtotics. As I describe - and I got from my podiatrist: He sees them as a temporary fix - like a splint or cast that gets used on a limb. BUT - when the acute problem is healed - get out of the orthotic so the foot can move again.
http://jimhaselmaier.blogspot.com/2010/02/orthotics-temporary-or-long-term.html
There are foot exercises that can be done. And just walking barefoot can help as well.
Jim