What is the most annoying cell phone abuse you have encountered?

For me, it is using cell phone on the bus. I used to take the bus. Sometimes on my way home, I wanted to take a nap. But there were always some people who had to make or take a phone call, and they had to talk very loud. It was real annoying. Makes you wonder where these people learned their manners.

One time, a guy was talking on the cell phone so loud as if he was trying to make a statement to everyone on the bus, "see I just got a cell phone".

Where do I start
- I can't stand the guy who feels he needs to yell into the phone because he thinks he's SO important. This is most annoying on planes where its a tight space and you can't just walk away.

- Driving and talking. I've almost gotten hit by bad drivers later to find they're talking on the phone.

I could go on but as you can see its a big pet peeve of mine. I keep hearing they may allow cell phone use on planes...and I travel a lot. This could be the worst idea ever...if that happens, I'm going to the John Madden route, and take a bus everywhere.