Also, I see these cities represented pretty well in discussions of "most active / most fit" and "environmentally friendly" US places. Living for 25 years in New York and Connecticut, I'll say this: I've listened to thousands of more criticisms of Florida being one strip mall than I have of it being too much for the elderly. Cut this crap out of Jacksonville being where Florida begins.
IMHO, I think Jax also would do well to better publicize its large urban park system and find ways to create lengthier green stretches for biking, walking, caneoing, etc by linking parks (i.e., the idea of cleaning up Hogan's and McCoy's) and providing urban green pathways (okay, the last one might be out of reach financially right now).