City Daredevils!

BASE Jumping.  Parachuting off a fixed object instead of a moving one. Daredevils jump from antennas, bridges, cliffs, high rises, and waterfalls.

Parkour.  This performance art was based on military course training. Participants negotiate a setting using athletic skills, gymnastics, and no equipment.

Tightrope Walking.  A balancing act of walking on a rope. Perhaps the most hand sweating one I have seen involved the Twin Towers.

Climbing Buildings.  Alain Robert, known as the French Spiderman, is perhaps the most famous of these daredevils. 

Subway. Enough adrenalin for the average citizen.