The listing, Rearview Spy Glasses Mirror Vision - See What's Behind You! - Free Shipping has ended.
I got the idea to feature these from a Huffington Post series on inventions you wish you'd though of: http://www.huffingtonpost.com/2010/07/12/why-didnt-i-think-of-that_n_643458.html#s113142
This presumed clone of the idea actually get quite good reviews as toys in Amazon:
http://www.amazon.com/Rearview-Sunglasses-Rear-View/dp/B0006GK6W0/ref=pd_sbs_t_3
There are five reviews of four and five stars and one with a one star but the one star reviewer said she would have left five stars but the system would only let her leave one.
The value of the product is only $2.97 but if it passes 222 credits I will send out two glasses by drop ship.
Amazon description:
"The special secret coating gives you "rear vision". You can spy on stuff behind you! These specially made sunglasses have a mirror on each side allowing you to see whats going on behind you. Very cool sunglasses for any age. Kids love using them along with teachers to keep an eye on students. You can also use them as cool looking sunglasses. UV400 meets general purpose UV requirements."
Free shipping.