Oh, I wish I could help you! If I remember correctly, they found it in the computer cases aisle - tucked away in a corner. It was right by a kid's cover (at least, the cover had a very childish cartoon on it). To be honest, it was quite by accident that I found it...
This was the THIRD Best Buy store I had been to, looking for this thing (really didn't want to wait for my pre-order to ship ... figured it was worth a shot). Well, I called one - but still! The sales clerk's have no clue! The only thing they are good for is looking in their computer to tell you "yep, we have x-number on hand, but we don't know where they are."
The only advice I can give you (or your son) is to just look through the whole store. Check the keyboard section, the iPad section, the case section, etc. Here's a link to a picture of what the package looks like:
http://static.seekingalpha.com/uploads/2010/11/24/500579-129060954168542-Worthless-Pennies_origin.jpg. Maybe that'll help.
Good luck on your search. Actually, I hope ZAGG.com sees this post. Because they need to know how poorly Best Buy is doing at having their product available for customers...
Anyway - good luck.
Marliyn