I got the GoPro 3 Black edition around Christmas time. Admittedly, I don't use it as much as I like, but I love the thing. I've used it for fishing several times with the head strap. Also mounted it on my car and boat while riding around. Used it while playing football with some friends.
I am taking a trip to the Caribbean in a couple of months and really looking forward to using when I snorkel and go deep see fishing
Here's a couple of pics mounted on the hood:
Also made a really cool video driving the ice roads in Canada