The more I work, play, live life, talk with people, drink coffee, enjoy cigars, travel, spend time with family, and the like, the more I am convinced that there really is a time and place for everything. For example, you wouldn't email clients while attending your mother's funeral. Not only is it rude to your mother, but you are probably not in the best state of mind to be in communication with the people who are paying you for a service. (This actually happened to me. My rep from ADP was replying to my emails while at his mother's funeral. His responses were everything but professional).
You are at dinner with friends. Notice how you (and them, probably) keep looking down at your phone? Turning on the screen to see if any new notifications came through, turning it off, and repeating this during the entire meal.
I do this. A lot of my friends and family members do this, too. Rude? Heck yes. Socially acceptable? Heck no (well, maybe it is, but probably not in a majority of cases). Do we do it anyway? Yep. Why? We're bored, and we need to be in constant motion. Stopping to talk with the person at dinner means that we could be missing out from 5 or so conversations on Twitter, Facebook, LinkedIn, etc.
Here's what I've noticed, and it isn't anything new: when I purposely put my phone in my pocket and don't allow it to vibrate (and thus distract me) the quality of conversation I have with the person or people I'm with goes UP in a big way. When I leave the phone out, I'm lucky if I remember what we talked about the next day.
You are driving...this one is even more obvious. Just don't do it. Put whatever it is away and focus on the road. Please.
I could sit here all day, or night (it is 1am as I write this), and recount examples from my life where I've tried to do one thing during another thing and the two things just didn't jive. What I've noticed is that multitasking is over-rated.
Here's a promise I can make to you: you will be a better sale rep if you don't email your clients while at your mother's funeral. You will be a better friend/spouse/parent/etc if you value the real people around you instead of the virtual people on your phone. You'll be a better driver if you focus on driving and nothing else. Name what you want to be good at. Make time to do just that and nothing else at the same time. You'll notice an uptick in overall quality of whatever it is you're doing. Guaranteed. Do this today.