I have a cell phone and I know lots of people do. I think they are incredibly convenient. I just wish that people would learn a little bit more about them and think about how it affects the people around them.
So, you're sitting somewhere and you hear a cell phone - a common occurance. You see people funbling around for their phone trying to get it while it is ringing. Then, as it's still ringing, they look at it to see who it is that is calling them. It's still ringing, even though they obviously know that someone is calling, while they are trying to decide if they want to answer it or not. It generally doesn't take people very long to figure out if they are going to answer it or not, maybe a couple seconds. But, it is ringing the entire time - long after they need it to be ringing.
Many cell phones have at least one button on the outside, even if it is a flip top phone. It's fairly standard and can most likely be customized to make these buttons turn off the ring. This will not affect the person calling. It will not send them to voicemail or hang up on them, it will simply stop the phone from ringing and save everyone from hearing whatever annoying sound your cell phone is set to make.
So, the phone rings. The owner fumbles around looking for it, and finds it. As they pull it out of their bag, they simply push that button and it is silent. They can look at who is calling, while it is silent, and decide if they want to answer it. It takes almost no more effort for them and is much nicer for everyone around them.
Knowing this can also save you in embarrasing situations. I very often forget to turn my phone to silent before meetings, but being able to turn my phone off quickly can turn an interrupting noise into a relatively unnoticed situation. When my phone goes off, I just grab it and, through my pants, can turn it to silent. Many times, if you don't make a big motion, you can do this and people won't even know whose phone was ringing.