If you take photos, you need to know what your rights are. These days, the police, private owners, and people in general have become wont to tell you that you can't take pictures of stuff. They'll even try to take away your camera or film.
Now, you can know when to tell them "No."
Photojojo, a great photographer's resource site that I recently discovered, has "The Ten Legal Commandments of Photography," as well as links to complete listings of your rights vis-a-vis the law. Granted, if you tell someone "no" when they don't want to hear it, you're gonna be in a pickle. But at least you can know that the law is on your side if you want to see things through to the end, legal recourse and all.
Previous P-jo (yeah, I already made up a nickname for it. What.) posts of interest include:
How to love Polaroid film in these, its last days
Faking Cross-Processing with digital, and loving it