Do It. I've been before. It was a lot of fun. It's a lot more tame than most people make it out to be. Basically, it feels like you're floating--you don't get the falling sensation except for two times :
1) immediately falling out of the plane
2)when you first pull the 'chute
the whole jump is pretty nice. if you're going up, try to get the pilot to go another couple thousand feet higher. it makes for a longer jump, and 2000 feet higher isn't much to worry about (oxygen, that is). it's a pretty good adrenaline rush, and i suspect that if everyone knew how tame it was, there would be a lot more people doing it