Bungie is running Be a Hero campaign! You can help get money donated to Haiti, just by playing Halo. You need to play by midnight Pacific tonight (Thursday 1/21), and change your logo to hearts. Here are the steps for changing your emblem.

Edit your appearance settings so your character is wearing the RED HEART emblem.
a. Press START
b. Select “SETTINGS” / “APPEARANCE”
c. Select “EMBLEM”
d. Select “Hearts” ICON, “Circle” BACKGROUND
e. Back out to the APPEARANCES menu and select “COLORS”
f. Set “EMBLEM PRIMARY” to RED (or MAROON / BRICK / ROSE depending on which game you’re playing!)
g. Set “EMBLEM SECONDARY” to WHITE

Make sure you play a game online after you update your emblem

You can also buy Bungie Apparel and Bungie will donate the profits to Haiti.

Thanks to Major Nelson for the heads up.