The awesome event in which you and a group of homies get some chalk and choose a random person's house- You should probably somewhat know the person. Then one of your homies lies down in the driveway of the random person and you outline the body like a dead person. You then take a picture and post to Facebook, Twitter, or whatever shabang you use and let the person find and outline of a body in their driveway!
"Bro!!!! Let's totally go chalking at Martin's house!"