I'm a PF sufferer too and also a runner. I took 6 mo. off from running last winter, got better, but now I'm back to where I started. Anyway, I can give you a few tips, but keep in mind, that none are cures...just ways to deal with the pain. Here is what has worked for me: ice after every run, 800 mg ibuprofen twice a day (or some other anti-inflam), stretching (actually can cure it if tight calves, hamstrings, or achilles is the problem), deep tissue massage (helps break up the scar tissue). Also, I believe it's very important that you cut back on your mileage as much as possible. Ideally, you should only run every other day and I'd recommend eliminating any speed work and try to stay on soft surfaces...trails, beach, etc. If I were you, I'd even try taking off 3-4 days (while taking ibuprofen)...maybe even a week. Just a short break might be enough to get rid of it if you have a mild case. It is my belief that you can get through a marathon on limited mileage (~25ish) if your goal is just to finish. However, the best thing for you is rest and then figuring out what caused the problem to start with...orthotics are a good place to start and about 90% of runners need them. Tip for orthotics...ask around before chosing a doctor to make your orthotics...you want someone who knows about running and PF. good luck.