Jimmy Carter — was president, is blogger.

Former US President Jimmy Carter has a blog:

"Carter and his wife, Rosalynn, are traveling in West Africa Feb. 2-7, 2004, on behalf of The Carter Center. The purpose of their trip is two-fold: to call international attention to the need to eliminate the last 1 percent of Guinea worm disease remaining in the world and to launch the Development and Cooperation Initiative, a multiyear effort to help reduce poverty in Mali.
Members of the general public can accompany President Carter virtually as President Carter blogs, or publishes regular journal entries from the field. Reports will be posted as they are received from President Carter, who will share his thoughts and feelings during his journey in West Africa."

Link
(Thanks, Jean-Luc)