All across the country, devoted college basketball fans (and less-devoted basketball fans) have etched out a bracket of who they think will advance in each round of the NCAA Tournament.

It was hard not to hear about the start of March Madness on Thursday morning, whether it was in a water cooler conversation or on social network sites. An estimated 50 million Americans participate in March Madness office betting pools, according to MSN, and 86 percent of their survey respondents said they spend at least part of their work day following the tournament.

For the fourth straight year, President Barack Obama is weighing in with his picks. Obama chose North Carolina to win the tournament, with Kentucky, Ohio State and Missouri also making it to the Final Four.

Wisconsin and Marquette both advanced in the first round of the tournament today. The fourth-seeded Badgers will play fifth-seeded Vanderbilt in the next round Saturday at a time to be determined. Marquette, a No. 3 seed, will play sixth-seeded Murray State Saturday, also with a time to be determined.

The top-seeded teams this year are Kentucky, Michigan State, North Carolina and Syracuse, but it's anyone's tournament at this point.

Tell us in the comments, who you're picking to go to the Final Four and the championship game — or whether you even care about the tournament.