PA Bowhunter/RWK-
I picked the puffball to show my wife and kids. I had no idea at the time it was edible until I researched it on line. There is one similar mushroom that is poisonous, but it has gills. Puffballs are solid and all white inside, sort of like a giant marshmellow. Nothing else looks like them. Interestingly, this thing grew from the size of a softball to abasketball in only 3 days (I ignored it the first time I saw it, but after it grew like it did, Ifigured I had to pick it.)
If you like mushrooms, I would highly recommend you try one of these if you find one. Little butter, some onions and voila! Very tasty on bread. Just make sure you cut it open to make sure it does not have gills!