What's happening today and what will be the talk around the watercooler.

Watercooler talk: "Hunger Games" opens big, and James Cameron starts a historic dive. See a video report here:





What’s happening today:

- The U.S. Supreme Court today will begin hearings on President Barack Obama's 2010 health care law. The hearings run through Wednesday and will decide the law's constitutionality.

- A rally in protest of the shooting death of Trayvon Martin is expected to take place today in Sanford, Fla., the town where the teenager was shot to death.

- Pope Benedict XVI is expected to visit Cuba today. It would be only the second visit to the nation by a pope - Pope John Paul II visited in 1998.

Opening bell: The Dow opened at 13,080.73 today.

Gas prices: GasBuddy.com reports today’s lowest gas prices are in Wyoming ($3.448 a gallon) and the highest are in Hawaii ($4.503 a gallon). According to the Lundberg Survey, gas prices have risen 11.49 cents in the past two weeks.

Motivational quote: "When one door of happiness closes, another opens, but often we look so long at the closed door that we do not see the one that has been opened for us." - Helen Keller

Weird news: A British couple jokingly invited Queen Elizabeth II to their wedding when they heard she would be in the same area, but they never expected her to show up. Buckingham Palace initially said no but secretly arranged a meeting, and the queen showed up and posed for photos and talked to the newly married couple.

GateHouse News Service