Dad, I love you dearly, but holyfuckinshit you need to learn how to use a phone in 2010.
1) Call Waiting is not the epitome of rudeness and your phone will tell you who is calling on the other line so that you can decide whether or not you want/need to answer. It's been, like, fifteen years. Accept the beep. This is how phones work now.
2) Carrying around a cellphone is USELESS if you leave it off all the time. Turn it off in situations that call for it, and put that motherfucker on vibrate the rest of the time. If the vibrating is too much of a sonic intrusion, there is an ignore button that will dump callers into your voicemail. If you're going to only turn it on "in case of emergency", then stop telling people you have a cellphone.
For the love of Pete, get with it. Phone technology HAS changed a lot since your heyday, but it isn't rocket science. Answer your phone!! —Vince Coleman, Dispatcher