Originally Posted by Trisk

Actually, If I was standing on a subway with someone and they just turned to someone else in the middle of our conversation and started talking to them, I would be kind of pissed off. It's rude. You can finish your conversation with one person and start another with someone else somewhere else, but completely excluding one person from a conversation you are having right next to them is bad behavior, especially if you abruptly ended the first conversation.
That's why talking on a cell phone with someone for an hour when you're with someone else in person is so rude. At least when you're talking to someone else that's there with you, the third person has the option of joining the conversation. With a cell phone, it's a one-on-one conversation. The third person is just a rejected onlooker - listening to half the conversation but unable to give any input. When people get together, it's generally for some type of social purpose. Talking to someone else on a phone the whole time kind of ruins the whole point of getting together.

Generally, I'm not going to whine and bitch about cell phones. If you do that to me every time we hang out, I just won't hang out with you as much (and when I do, I'll remember to bring a third person). Hell, I don't even care if it's a fifteen minute call. Anything over that, though, is pushing it. Do you really need to bitch about your boyfriend to whoever's on the phone for an hour when someone else is in front of you? If you have something you need to get off your chest, tell it to the person that's with you and call the person on the phone back later.