Roll a paint roller up and down your shins
"Before running roll a paint roller up and down your shins." source: answers.yahoo.com
Yip, you read it right. Now I would think this is a very bad idea. Thai boxers roll rolling pins up and down their shins to kill nerves off, so when they striking with their shins, or blocking other peoples kicks - they can't feel it.
I don't think I'll be trying this one.