Er you must write for the Reg!

The problem with your idea is that you'd have to have some form of facial recognition to identify the hooker. Depending on the shift, the window worker changes. So maybe they place bar code placards in the windows to identify the hooker? (Since the Dutch regulate the industry and the hookers are supposed to be registered, they should be able to post something to identify them, right?)

Then your phone can get their bios and their latest blood tests for any sexual transmitted disease information, or if they're running a special and will offer an instant online coupon if you transact your business using your phone's EFT feature?

No, my minds not in the gutter like Tony72, but I just like to solve problems. He just made it sort of interesting and fun. :-)