YOU COULD NEVER GET ME TO DO THIS... I'm so scared of heights.
Late last month, two tightrope walkers in Spain attempted to walk from one hot air balloon to another across a "slackline," which is like a tightrope but wider. And they did it while they were 10,000 FEET in the air.
The first guy fell immediately and managed to catch himself, but neither of them made it the whole way across. Obviously they were both wearing parachutes.