During my year of intense photography I was only questioned five times. After the first time I learned what my rights were and now carry around this sheet in my camera bag. Other good resources:
http://www.krages.com/phoright.htm
http://www.kantor.com/useful/Legal-Rights-of-Photographers.pdf
Here are the five situations, how I did react, how I would have reacted if I knew my rights, and the outcome.


Monterey Airport
This is the one that really gets me, and if I understood my rights better I would have reacted differently. My son and I were standing just outside the fence at the airport photographing cool planes. We were next to the MillionAir terminal, which is where many private planes use as their main terminal. One of the Gulfstream jets was boarding some people and a security guard who was with them came over to me. Through the fence he asked me what I was doing there. I told him “taking pictures of planes” (duh). He then told me not to take any pictures with tail numbers in them. I said okay. After he left I kept shooting (tail number or not). He had no rights regarding my photography at all. I was on public land and could shoot whatever I wanted to. I could have zoomed right in on his face and fired away, I could have shot all the pictures I wanted of his clients and their plane. I was unsure of my rights at the time, which is what prompted me to learn more. If it happened today I would politely explain that to him, and probably take a picture of his plane just to make my point. Then he’d probably punch me, rights or no rights.

Geckos
Yo, Chameleon
Petco
The second time I was shooting in one of their stores an employee came over and told me they didn’t allow photography in the store. He was very nice about it and I was happy to stop shooting. I love the shots I got that day.They were totally within their rights and I quit shooting.

Self Portrait on Escalator

Hollywood & Highland Center (Kodak Theatre)
I was shooting late at night, but the mall was still open. I was trying to get a self-portrait in some mirrors hanging within a set of escalators, so I was riding the escalators up and down and up and down… A young security guard came over and told me they didn’t allow photography there. This isn’t true, since it’s a tourist trap and people are taking pictures there all day. Though I didn’t believe her, I was polite and simply asked “Why not?” She stumbled for a moment and then said they were afraid the security cameras would be in the pictures and that would compromise their security at the mall. Okay, there’s a million holes in that reasoning, but I was done shooting anyway, so I thanked her for letting me know and turned to leave. She then thanked me for being so nice about it. Since I was on private property, they do have the right to not allow me to take photos, and to kick me off the property if I continued. So she was within their rights, even though the reason was really bogus. I would have liked it if she just said I was creeping them out and had to stop.

DIY Paradise

Auto Parts Yard
This was in LA. I paid my entrance fee, signed a document that I didn’t read (I assumed it was about how to collect and pay for parts) and went in with a backpack filled with camera stuff. I spent about 45 minutes taking pictures and being pretty conspicuous about it, including standing on top of cars to take wide shots. When I was leaving they checked my bag and saw all the camera stuff. The gate person asked if I took pictures and I admitted I had. She then said I needed to talk to the Manager and had me follow her back out to the yard. The Manager told me photography wasn’t allowed there. I was expecting more, but that was it, so I turned and left.They were within their rights to not allow photography there, with or without notice. It was probably in the sheet I signed though. However, even though I took pictures they aren’t allowed to inspect my camera, make me delete images or confiscate cards, film or equipment. So the most the Manager could really do is tell me not to take any more and kick me out, which is basically what happened (except I was already leaving).

Railroad Bridge at Night

Healdsburg Bridge
I was shooting night shots of the bridge around 11pm, and on a moonless night it was pretty creepy in this small, dark park. After I had been there about 20 minutes a police officer parked nearby and walked down with his flashlight in my face. He saw I was taking pictures, so he was really nice to me. He explained that the park closes at sunset and that it isn’t a safe place to be. He then asked how much longer I was planning to be there. I had gotten my shot and was happy to leave at that point anyway, so I told him that and started packing up. I really appreciated how nice he was, and I felt like he was there to protect my stupid self rather than harass me.