NBC's Olympics coverage on Monday averaged 31.4 million viewers. By contrast, ABC, CBS, and Fox averaged 9.5 million viewers -- combined !. The only competing show on any of the other networks to attract more than 4 million viewers was CBS's rerun of Two and a Half Men at 9 00 p.m. Virtually every show on the competing networks was a repeat except for ABC's new reality show The Glass House , and that show drew a pathetic 1.67 million viewers. NBC is expected to continue to overwhelm the competition tonight (Tuesday) as swimmer Michael Phelps goes for his third straight gold medal in the 200-meter butterfly. If he's successful he will tie the record for the most career Olympic medals.