If you have ever sent a gift to a charity or non-profit orginization you know that you will get soliticitations and "updates" from them until you die. I ran across a blog post today from USA Today where the author suggests..."Try Internet giving sites. Network for Good and Justgive.org are non-profit groups that process online donations to thousands of charities. Both websites let you make anonymous contributions to the charity of your choice."
"Make privacy a condition of your gift. Look for charities that have a written policy stating that they won't sell or trade your information. Some charities let donors "opt out" of receiving solicitations. "
Either way, I suggest you always be careful when giving out your personal information, getting on the wrong list could make your phone ring for years.
What my wife and I do is practice cheerful giving while not telling the complete truth. (God is understanding.) We have a fake phone number we use for all of our bills, utilities, credit, movie rentals, and chairties. We use the same number so its easy to re-reference us by our phone number... you just can't call us there. We also each have a junk e-mail address.
USA Today Blog - Charitable givers can kiss a lot of junk mail goodbye if they're careful
Also, see this previsous post on Reducing Mail and Telemarkers.