If I could paint myself with special paint that made me invisible...

  I would visit all the "Secret Rooms" of the world.  For instance, when buying a car, you make small talk with white-teethed salesmen for as long as you can take it, and then when an offer has been made, they have to go take your offer their "people" to see if they can make that deal work. This can take anywhere from 10 minutes to 580 minutes.  I would like to know if they are actually running numbers to see how this deal impacts their dealership financially - or are they simply watching a game and shootin' the breeze?
Next I would slather up in the invisible paint and go visit the kitchen of the restaurant to where I just sent my meal back.  Are they actually carefully remaking my dish to my specifications - or are they simply spitting on it, throwing it the microwave, and ever-so-gently sprinkling a bit more cilantro on it?
And my favorite and final destination: ANY room that says: NO ADMITTANCE - the closest I have ever come to entrance into a room such as this is a Teacher's Lounge - but now they don't really put those signs out any more - it's more likely to say, "Teacher Workroom" - which isn't nearly as intruiging.

Silver Lining: When my son puts signs on his door that say things like "Boys Only" - he always writes in small letters at the bottom: "Except for Mom."  He knows a sign like that is only an open invitation for a curious mom like myself.