Old post but I liked it. However to keep up to date bungee jumping is more exciting and ideal for the scammers. You can buy suitable lengths of polypropylene rope with a 250 kg breaking strain and even tasty flecked stuff. For a jump off a bridge say 80 metres high you would need about 40 metres of rope per leg. 250 kg should provide a safety margin because we can't have it snap at the bottom can we.
The benefits are enormous because not only do they get an adrenaline rush, they get a sense of acheivement as well as a feeling of detachment.