This should go without saying, but if you have to use a Bluetooth device in public, could you just NOT make eye contact with other people? There’s nothing like being in an airport (or a mall, or a waiting room at a doctor’s office) and glancing up to see someone looking at you and saying, “Hey! How’s it going?” and then continuing to talk before you’ve said anything. Worse…you reply, and he/she shoots you an annoyed look while pointing to the tiny piece of plastic in his/her ear. Even worse, there’s an exchange you think is actually happening with this person who is oblivious…
Bluetooth Bob: “Hey! How’s it going?”
You: “I’m doing well… How are–?”
BB: “Great, great… So, hey, I need a favor.”
You: “You need a… What? Who are–?”
BB: “Can I borrow your car? I just need it for the weekend.”
You: “Whoa. Who the f–?”
At that point, Bob walks away, obviously chatting with someone on the phone. You look like an idiot, but the other people in Starbucks get a good laugh. You feel really stupid, so you write a blog entry about it.
Hypothetically speaking, of course.