The U.S. men's basketball team will head into the Summer Olympics unbeaten.  Team USA pulled away in the second half for a 100-78 win over Spain in its final Olympic tuneup on Tuesday.  It was a rematch of the 2008 gold medal game in Beijing, also won by the U.S.  New York Knicks forward Carmelo Anthony scored 23 of his 27 points in the first half for the Americans, who finished 5-and-0 in exhibition play.  Miami Heat star LeBron James added 25 points in the win.  The United States will open Olympic play with a preliminary round game against France on Sunday.