From http://vpizza.org/~jmeehan/balloon/:

Part 101 of the FAA Regulations covers balloons, kites and rockets. The first section of Part 101 spells out exactly which kinds of devices the rest of Part 101 applies to. Regarding "unmanned free balloons," Part 101 applies if the balloon:

  (i) Carries a payload package that weighs more than four pounds and has
  a weight/size ratio of more than three ounces per square inch on any 
  surface of the package, determined by dividing the total weight in ounces 
  of the payload package by the area in square inches of its smallest surface;

  (ii) Carries a payload package that weighs more than six pounds;

  (iii) Carries a payload, of two or more packages, that weighs more than
  12 pounds; or

  (iv) Uses a rope or other device for suspension of the payload that 
  requires an impact force of more than 50 pounds to separate the 
  suspended payload from the balloon.

people do this all of the time -- its a neat experiment for kids of any age

EDIT: It's even more fun with a lawn chair and a person in it http://en.wikipedia.org/wiki/Larry_Walters

'He was immediately arrested by waiting members of the Long Beach Police Department; when asked by a reporter why he had done it, Walters replied, "A man can't just sit around."'

What a quote!

I especially like the part (not sure if it was mentioned in the Wiki article) where commercial airliners were reporting a man in a lawn chair at 15,000 feet. I would have loved to be eavesdropping on some of those cockpit discussions. Hey Bob! Say! Is that a man in a lawn chair over there next to that cloud? Whah?

If I'm not mistaken, they've started an annual race or something in his name.

hahahaha

This is a story with a sad ending. I wonder why he did it?

Looks like it was the 'Nam.

Note I said online map, not Google Earth which is a desktop application. (Although it's still true for Google Earth.) Also note I said aerial rather than satellite, and Russia rather than e.g. San Francisco. It amazes me that such a simple sentence has been misunderstood on all three points. A sign of the changing times?