I have one on my D3100. I didn't mention in because in bright sunshine it's worthless. In moderate light it's ok. It does a much better job of protecting your LCD display.
They can be found all over e-bay.
I hear you Jake, I went with the Op-tech strap because of the easy removal of it. I am going to order the keeper straps they came out with so I don't have to worry about it unsnapping. The Bostail is for my BR metro strap.