http://bit.ly/bi65tHafter reading this i was interested to know more about this sport.so did a little google and .........hoh...........this is a really very popular stunt;but never heard about it before.
B.A.S.E. is an acronym actually:buildings,antennae,spans(i.e,bridge) and earth(i.e,cliffs)-you have to jump from all 4 to get a base number.
here are few lines from wikipedia:
The acronym "B.A.S.E." was coined by film-maker Carl Boenish, his wife Jean Boenish, Phil Smith, and Phil Mayfield. Carl was the real catalyst behind modern BASE jumping, and in 1978 he filmed the first BASE jumps to be made using ram-air parachutes and the freefall tracking technique (from El Capitan, in Yosemite National Park). While BASE jumps had been made prior to that time, the El Capitan activity was the effective birth of what is now called BASE jumping. BASE jumping is significantly more dangerous than similar sports such as skydiving from aircraft, and is currently regarded by many as a fringe extreme sport or stunt.
BASE numbers are awarded to those who have made at least one jump from each of the four categories (buildings, antennas, spans and earth). When Phil Smith and Phil Mayfield jumped together from a Houston skyscraper on 18 January 1981, they became the first to attain the exclusive BASE numbers (BASE #1 and #2, respectively), having already jumped from an antenna, spans, and earthen objects. Jean and Carl Boenish qualified for BASE numbers 3 and 4 soon after. A separate "award" was soon enacted for Night BASE jumping when Mayfield completed each category at night, becoming Night BASE #1, with Smith qualifying a few weeks later.
During the early eighties, nearly all BASE jumps were made using standard skydiving equipment, including two parachutes (main and reserve), and deployment components. Later on, specialized equipment and techniques were developed that were designed specifically for the unique needs of BASE jumping.