Caller ID shows "Operation Smile" They have called every few days without leaving any message. I called back and their recorded greeting introduces them as "Strategic Fund Raising". They are calling seeking contributions for either political or charity fund raising. Both types exempt them from the DoNotCall Registy's regulations. Wonderfully, you can press option 0 and have your phone number added to their own Do Not Call list. They said it's possible another call may arrive before their system updates with the new numbers added to their DNC list. Reasonable.
These folks are Operation Smile. It is a charitable donor company specializing in repairing cleft palates on children in developing countries. I gave them some money last year, but have been receiving a significant amount of emails and letters asking for more money.