Barack Obama’s Olympics ads strike a positive note, while John McCain’s ads take a more negative approach, The New York Times “TV Decorder” blog reported Monday.

The story noted that one McCain ad attacking Obama aired last Friday during the Olympics opening ceremony’s “parade of nations” — a procession of smiling athletes. 

According to Nielsen, that ad accounted for 30 seconds of the total 35 minutes of commercials that aired on NBC’s U.S. broadcast of the opening ceremony.

View Nielsen’s advertising data round-up for the 2008 Beijing Olympics opening ceremony.