Shoe inserts and stretches have helped mine by leaps and bounds. So has rolling a frozen peaches can under my foot (peaches! peaches for me! +2 cool score if you remember that song). Icing it RIGHT after I jog/walk has helped a lot as well.
I also ice it right after a VERY hot soak in water. While it was painful to the point I thought I was going to have to give up exercise, it's really just an afterthought now
And it's only been a few days!