Do you carry a gun hoping someone will attack you?
I know you don't, but the question sounds the same to me. I don't intend my response to sound rude and I hope you will take it in the spirit it was written.
I keep a voice recorder with me any time I'm in the car, in case I get pulled over so that I have a record of what the officer says. (I drive carefully and haven't been pulled over in 7 years, but you never know.) When I go anywhere open carrying I normally turn on the voice recorder, say the time, date, and address of where I am, then go about my business. If I had a video recording pen (they're available for sale on tigerdirect.com) I'd use that instead.
Anyway, I have a couple reasons for recording. One, in case I have a conversation about firearms. So I can remember everything that was said, analyze my responses, and improve for next time. sadly, I haven't gotten the opportunity to do this, because all the conversations I have had happened when I was without my recorder.
One reason is because of police. I have heard of police being very rude to people for no other reason than the individual was carrying a firearm.
The third reason is for protection against someone who might call the police and say, "there is a man with a gun in Lowe's and he verbally threatened me." or some such nonsense. I can produce an audio recording with the time and date that it never happened. Yeah, I know that's a long shot, but I still like to have it.
There are some recent audio recordings on youtube that make the case for having an audio recorder going. Perhaps you heard the one from Philly. There are some from a michigan open carry group as well.
the last reason is for the "open carry naysayers" who have said things like "you can't carry in a grocery store, they will throw you out." or "you will be targeted by bad guys" or "you will scare kids and they'll run away screaming." A good response to those is to say, "here, listen to this. I went shopping for 20 minutes in target yesterday and here's how it went." It's really boring to listen to, because nothing ever happens.