Back when I was running every day and training for marathons, I found that a useful tool for plantar fasciitis could be massaging the affected heel three or four times daily for about 10 or 15 minutes with a cylindrical object like a wooden dowel or small rolling pin. Just rolling it over the area, not really hard but with enough pressure to get the blood flowing.

That's certainly not a cure, because those micro-tears in the fascia have to heal. But I'm pretty sure massage and increased blood flow can cut the healing time some.

Other runners seem to agree, and at worst, the massage doesn't hurt anything.