After a month of biking and pool-running to allow my left tibial stress-fracture to heal, upon prematurely concluding that I was fully healed I ran three days in beautiful downtown Chicago. Though the first two days were a glorious return to running with absolutely no discomfort or pain, on the third day I realized that I'd returned too quickly to my favorite passion - and by doing so almost certainly lengthened the time required for my stress-fracture to fully heal.
Lesson learned and word to the wise - avoid the huge temptation to deviate from the well-proven pool-running and other non-impact activities until any and all discomfort associated with the stress-fracture is completely gone (and preferably until your G.P. gives you the green light!) When you do return to running do so gradually, almost as though you were a beginning runner.