-- Odds are, your friends have posted videos of themselves to Facebook that depict them dumping buckets of ice water over their heads as part of the #ALSIceBucketChallenge.
Now you can add Justin Timberlake to that list.
The singer accepted a nomination from Patrick Downes and Jessica Kensky, two survivors of the Boston Marathon bombing, and challenged Jimmy Fallon and the Roots to follow suit.
"You've got 24 hours to donate AT LEAST $100 or douse yourself with ice," he wrote to his celeb pals. "Or both. We did both...and then we donated a bunch more. It's such a good cause. To donate: http://alsa.org/donate/."
To watch Timberlake and members of his back-up band, the Tennessee Kids, go through with the deed, watch the video below.