Today's Buzz: the 50 best comedy sketches of all time -- with video! Is Katie Couric getting pushed out at CBS? Magnesium deficiency linked to aging faster, all eyes on torrid Tiger, more flights grounded, and more.

Today's Buzz: Clinton on the ropes after Indiana and North Carolina primaries, misery in Myanmar, another reason to quit smoking, the 5 most dangerous roads in the world (with pics!), and more.