I don't know about your cockamamie, gigantic, mylar balloon project, but mine is not in our backyard; it'll be in the Pantheon or the Grand Palais. Or outer space. Still, I made the kid promise me she wouldn't climb into any satelloons without a grownup.
[Truth be told, all the channels in our house were tuned to Diarrhea And 103+ Fever That Doesn't Go Down So We Take Her To The Pediatrician At The Exact Same Time We Have To Do Pickup And Ballet Class Girl, so we missed the entire Balloon Boy story completely.]
That story really had me freaked out there for a while. The real question is who the hell has a balloon like that tied up in their yard? Apparently these people did. But, I've never heard of that. Why would a person even want one? very weird. I just use the weather channel.
I would totally want one. And I was halfway rooting for the kid to be in the balloon, as long as he made it back to the ground without major trauma. Adventure!