Flights out of Chicago have already been canceled; expect major travel delays.
Global Sentinels: Argentina's Penguins
"Nightline" travels to Patagonia to see world's largest penguin colony.
American Airlines to Charge $8 for Blankets
Coach passengers will now pay $8 for a blanket and an inflatable neck pillow.
Exclusive: Michelle Obama: 'Let's Move' on Childhood Obesity
First lady on "very ambitious" plan to end childhood obesity in a generation.
Palin Favorite Paul Ryan Rules Out 2012 Run for President
Rep. Paul Ryan, a Wisconsin Republican, is ruling out a 2012 run for president.
WATCH: The Conversation: Consumer Help
Natalie Neff and Farnoosh Torabi solve viewers' problems on "Fed Up Friday."
WATCH: Living Through the Storm
After a weekend of storms the east coast braces for more snow.
WATCH: Prosecutors Charge Doc for M.J.'s Death
Dr. Conrad Murray is charged with involuntary manslaughter for singer's death.
WATCH: New Orleans Celebrates Hometown Heroes
Ryan Owens gets reactions to the Saints' big win from Hurricane Katrina victims.
WATCH: The Magic Behind Those Super Ads
Diane Sawyer looks at the stories behind popular Super Bowl ads.
WATCH: Is GOP Becoming the Party of No?
Lately, Republicans have even been saying no to some of their own ideas.
WATCH: Michelle Obama's Battle Plan
The first lady discusses the fight against childhood obesity with Robin Roberts.
