We got some reflective film for my son's bedroom the other day. It gets so hot in there we had to do something - and it works great.
When you look at our house now you cannot see in his upstairs window, which is kind of cool - literally.
Naturally, being guys, we celebrated this interesting phenomenon by standing naked in his bedroom and waggling our willies at the neighbours across the street who could not now see us doing so.
In fact, we did this several times, until we learned that the hiding effect only works during the day. At night the process reverses, such that neighbours can see in but we cannot see out.
We learned this from a neighbour. Who called.
Not sure if she had a video camera, and she wasn't telling.
I hate it when this happens.