Source: Seura

A HDTV hidden behind your bathroom mirror- very cool.  You only know it's there when it's on- otherwise it disappears and all you see is the mirror.  Necessary?  No.  Luxurious?  Yes.

Sure, like almost anything else, you can DIY-it to save money, but dealing with the moisture and heat is the biggest risk.  Several manufacturers make these mirror TV's today to function in the bathroom environment.  Is one in your future bathroom renovation?