I must be high

From An Introduction to Cluster Ballooning:

To control the altitude of the cluster balloon, the pilot takes off with more balloons than needed to lift his or her weight, and carries ballast (water or sand) to balance out most of this excess lift. To level out or descend, the pilot releases or bursts balloons. To slow the descent or ascend again, the pilot releases ballast.

Ya know, if that was me hanging up there at 5 or 10 thousand feet, I think I'd be dropping a bit of my own personal ballast if you know what I mean.

If all this sounds a little familiar, you may be thinking of Larry Walters aka "Lawnchair Larry" and his 1982 stunt in which he tied 42 helium-filled balloons to his Sears lawnchair and drifted around at 16,000 feet for a few hours, disrupting LAX air traffic. The FAA arrested him when he landed and fined him $1,500.

A guy named Mark Barry runs the Official Lawnchair Larry website, and even has recovered the lawn chair used that day.

PS. For your listening pleasure, you can liten/download this cute song from John Forster on everyone's favorite noble gas.