If you don’t know what the #IceBucketChallenge is, the basic concept is someone pours a bucket of ice water over their head, at the same time challenging a friend or co-worker to do the same within 24 hours. You post the challenge and if it is not met, they have to make a donation to ALS. Justin Timberlake accepted the challenge from 2 Boston Marathon survivors, and then challenged Jimmy Fallon and The Roots to do it next: