I have found the follow website a good starting point for foot pain research: http://foot.com
From this website, consider the following:
Metatarsalgia is a general term used to denote a painful foot condition in the metatarsal region of the foot (the area just before the toes, more commonly referred to as the ball-of-the-foot). This foot disorder that can affect the bones and joints at the ball-of-the-foot and is often located under the 2nd, 3rd, and 4th metatarsal heads Metatarsalgia is often caused from improper fitting footwear.
Don't know if this is quite what you are feeling. I had this pain earlier this year and was able to rest, rehab and change shoes to help with the problem.