Obama spends $5M. You are actually right about McCain. I googled and found that his campaign decided at the last minute to buy $6M. Have you seen any of his?
No. I saw one McCain ad in Houston in early July just before I left the U.S. I also saw one Obama ad in St. Louis literally the night before I departed.
I haven't seen any of the Olympics. They come on at weird times here. I did see a tape delay broadcast of some of the opening ceremony. We get Armed Forces network, so we don't get political ads at all. (Which is probably a blessing.)