Everyone was telling me they saw them everywhere too - Target, Gamestop,
Walmart, but when I went to those places, they didn't have them, they had empty boxes sitting on the shelves where they should be as a marketing thing. My mother told me she had just seen three at Target that morning, I went right there and was told they didn't have them and hadn't in days - I said "but my mother saw 3 here this morning" and they pointed to the shelf where there were 3 empty boxes sitting as display. Walmart and Gamestop do the same thing. The ones that actually have a sensor in them are in the back, or behind the counter...they just put empty boxes on the shelf to advertise them.
So I did have a hard time getting one, but ended up getting one, (this was like a couple days after they came out though) at Gamestop. Go to a couple of different locations and find one where they are helpful. There is one near me where the manager told me what time their shippment comes in each day. I showed up every day at that time and he would unpack the box and for 2 day there weren't any, but on the 3rd day he had 4 come in and I was there as he unpacked them.