I don't frequent the water parks in the winter, even though I live here. So the last time I was at BB or TL was in 2006, and back then, when they snapped your photo in the lazy river, they gave you something waterproof to claim the photo later (I think it was a wristband or something). I don't think the PhotoPass system was part of it then.
Now in 2007, I see something different: a little hard plastic square with the PhotoPass artwork on it, a little like a supermarket discount card meant to attached to your keys. I haven't seen this in the (regular) parks too, but is this now what PhotoPass looks like everywhere, rather than a credit-card sized piece of plastic?