I don't mean to be a kill-joy, but I just wanted to add my .02 that puppies should be seen as additions to the family and not as gifts. They need to be trained, cared for, and like a PP said, they chew EVERYTHING while those adult teeth come in (we're in the throes of it right now with our ~7 month old pup.)
Don't get me wrong, dogs are great members of the family and are great for sharing lots of love...just a big life-changing commitment that shouldn't be taken lightly. And yeah, I also agree that the post that mentioned 45 minutes is an eternity for a puppy to be alone on their own accord. I, too, had forgotten what puppy was like since our last dog was 14 when we said goodbye this past year, I'm guessing that poster has an adult dog and has forgotten what it is like to have that busy energy around the house.