Clyde...are you the same Clyde that posted a while back on another foot or lower leg issue?
Amy dealt with P.F. for like 2 years. Eventually she went and had some manual therapy done on it that helped get rid of it. The manual therapy basically hurts like a mother, but breaks up all the adhesions, etc. in the tendons and fascia.
Plantar can be a tricky one, and for everyone who says it can be cure by 'forefoot running' you will find another that says it can be cured by 'heel striking'. But, the things that helped more than hurt when Amy had it were...
- Warm it up like Matt said;
- Keep the soleus loose by light massage (that's not the glamour calf muscle, but the smaller one);
- Less stretching of the foot and arch
And, as I wrote before, she actually started to 'walk (run) this way' as Doc puts it. She got further back on her foot (heel) and just ran relatively slowly for the first few months while learning that. She's now been running consistent with no interruption for like a year and is running better than ever. That all assumes that you've done some of the other suggestions you can find on the forum...
- move your cleats back on your bike shoes;
- Look at changing your run shoes around.
This thread has some really good info in it...http://www.teamtbb.com/forum/index.php?topic=2169.0