and as far as begging from charities, once I recognise what the call is, I say to them -
"we made a decision a year ago to donate to three charities twice each year. Unfortunately yours is not one of them."
It's true and works every time.
PS - we are on the do not call register mentioned. Yes it makes a big difference. And if you do get a caller that's not a charity once you say you on the register they depart quickly.