"Sen. Barack Obama, right, claps hands with his grandmother, Sarah Hussein Obama, at his father's house in Nyongoma Kogelo village, in western Kenya, in this Aug. 26, 2006 file photo. Obama's two years in the Senate have taken him around the world, from Russia to Iraq to Kenya - a travel itinerary more ambitious and more costly than any other senator who took office with him. (AP Photo/Sayyid Azim, File)"