On the same day Bill Clinton praises Sarah Palin, he announces:

New York – Former President Bill Clinton today announced the program for the 2008 Clinton Global Initiative (CGI) Annual Meeting to be held September 23-26, in New York City. …
Both United States presidential candidates will have a role in the Annual Meeting. Senator John McCain will deliver the opening remarks live at the “Integrated Solutions: water, food and energy” plenary session. Senator Barack Obama will address meeting participants via satellite.