Is a camera a nuisance?

[M_Six]

The link off the main page about some NY restaurants banning food photography revived an uncomfortable feeling of guilt I sometimes carry. I often wonder if my camera, or more specifically, my use of my camera, is a nuisance. We were at a nice (but not exclusive) Mexican restaurant in NYC a year ago and I took a shot of a table-side Guacamole preparer as he was making our guac. I had my gripped 7D and the Roki 35mm mounted, which makes for a large rig. When I pulled it out of my messenger bag, our guest, a friend of my wife, made a non-critical comment about the size of my camera (like, "Wow! That's a big camera!") and laughed. I asked the guac chef if he minded if I took his pic and he said no problem. I took a couple shots and put the camera away. But this article has me wondering if I missed annoyed glances from those seated around us.

Fast forward to this past fall, we were attending an exclusive lecture by a well known author at the Tower of London. I asked the author (who knows my wife well) if she minded if I took some pics and she was thrilled. Her husband had a small P&S and was going to take some, but he said he'd much rather have me take them. I figured that was good enough for me and I stood in the back of the room during the talk and shot away. After the talk my wife was none too happy with me because she said I was annoying people in the audience with the camera noise. She said she saw lots of folks turn around and glare at me. (Although I saw this just once and moved well away from that person.) In the end the author giving the talk was very pleased with the pics, but I still carry the feeling of guilt and embarrassment knowing I was being a disruptive pest.

As a result of that incident, I'm now extremely sensitive about using my camera in any situation where the camera noise, or just the size of the camera, may be considered annoying. This is probably good that I'm more aware of decorum in my photographic pursuits, but I wonder sometimes if I'm unnecessarily missing good shots because of it.

To what extent do you folks consider your environment when shooting in public? Do you have any tips for discretely shooting in public?