AP Photo/Mary Altaffer
Dennis O'Mally, the self proclaimed "King of the Leprechaun" cheers on marchers as they make their way up 5th Ave. during the 251st annual St. Patrick's Day Parade, Saturday, March 17, 2012, in New York.
AP Photo/Lois Bernstein
Boats drop green dye in the Chicago River during celebrations for St. Patrick's Day Saturday morning, March 17, 2012.
PETER MUHLY
A young girl performs during the St Patrick's Day festivities in Dublin, Ireland on March 17, 2012. More than 100 parades are being held across Ireland to mark St Patrick's Day, with up to 650,000 spectators expected to attend the parade in Dublin.
VALERY HACHE/AFP/Getty Images
A picture shows the illuminated in green of the Monaco's palace on March 17, 2012 in the Principalty of Monaco, during the Saint-Patrick's Day.
Chris Jackson/Getty Images
Catherine, Duchess of Cambridge presents 'shamrocks' as she takes part in a St Patrick's Day parade as she visits Aldershot Barracks on St Patrick's Day on March 17, 2012, in Aldershot, England. The Duchess presented shamrocks to the Irish Guards at a St Patrick's Day parade during her visit.
Sandra Mu/Getty Images
The Sky Tower illuminates green on March 17, 2012 in Auckland, New Zealand. Sky Tower joins the Opera House in Sydney, and Table Mountain in South Africa in going green to celebrate St. Patrick's Day.
AP Photo/Peter Morrison
The St Patrick's Day parade makes it's way through the streets of Armagh, Northern Ireland, Saturday, March 17, 2012.
Brian Kersey/Getty Images
Zach Paul sits with Chamrock (cq), an Irish wolfhound, as he waits for the start of the St. Patrick's Day parade on March 17, 2012, in Chicago, Illinois.
Joshua Roberts/Getty Images
Green water flows in the fountain on the South Lawn of the White House in celebration of St. Patrick's day on March 17, 2012 in Washington, DC.
AP Photo/Alex Brandon
A group of friends show off their Irish temporary tattoos at Cavanaugh's Rittenhouse on St. Patrick's Day Saturday, March 17, 2012, in Philadelphia.
AP Photo/Lois Bernstein
Prime Minister of Ireland Enda Kenny, center, and Rahm Emanuel, center right, lead the St. Patrick's Day parade Saturday, March 17, 2012, in Chicago. To the far left is Illinois Gov. Pat Quinn.
AP Photo/Misha Japaridze
A St. Patrick's Day Parade is held in Arbat Street in downtown Moscow, Russia, Saturday, March 17, 2012.
AP Photo/Shawn Pogatchnik
From left Irish President Michael D. Higgins, his wife, Sabina Coyne and and his shamrock-capped military aide, Col. Pat Herbert watches passing performers at St. Patrick's Day parade in Dublin, Saturday, March 17, 2012.
AP Photo/Lois Bernstein
Marina Towers loom in the background of a green Chicago River, Saturday morning, March 17, 2012. Boats ride back-and-forth on the river between Wabash and Columbus Avenues, dropping dye into the river in celebration of St. Patrick's Day.
CBS News
President Obama drinks a Guinness on St. Patrick's Day at the Dubliner in Washington, DC, March 17, 2012
PETER MUHLY/AFP/Getty Images
Parade goer watches the St Patrick's Day festivities in Dublin, Ireland on March 17, 2012. More than 100 parades are being held across Ireland to mark St Patrick's Day, with up to 650,000 spectators expected to attend the parade in Dublin.
AP Photo/Vadim Ghirda
A man with a mouse on his hat is seen during celebrations of St. Patrick's Day in Bucharest, Romania, Saturday evening, March 17, 2012. Romanians and members of the Irish community gathered in the historic part of the Romanian capital to attend celebrations.
AP Photo/Patrick Semansky
New York Mets' Lucas May reacts after striking out swinging to end the second inning a spring training baseball game against the Atlanta Braves in Port St. Lucie, Fla., Saturday, March 17, 2012. Atlanta won 3-2.
AP Photo/Mary Altaffer
Cardinal Timothy M. Dolan greets marchers as the make their way up 5th Ave. past St, Patrick's Cathedral during the 251st annual St. Patrick's Day Parade, Saturday, March 17, 2012, in New York.
AP Photo/Mary Altaffer
Bagpipers march up 5th Ave. during the 251st annual St. Patrick's Day Parade, Saturday, March 17, 2012, in New York.
AP Photo/John Heller
U.S. Vice President Joe Biden, bottom left, greets people as he walks in the annual St. Patrick's Day Parade in Pittsburgh, Pa., Saturday, March 17, 2012.
