Staring at windows.

The great thing about being in a crowded, busy and public city like Cambridge (I'm talking downtown here) is that you're unlikely to get arrested for staring long and hard at windows. Of course, it helps to be a woman. Other than the fact that I may have made the facilities manager at one of the colleges very nervous, I live to tell the tale.
    Windows. They make great reflections of the outside world that we tend to ignore. Unlike water, they're vertical. Go stare.