According to Paulo over at Eater, "Cold Stone Creamery locations will be giving away free ice cream from from 5pm to 8pm" today. (Eeeps!) Your choices are as follows: marshmallow ice cream with Oreos, chocolate chips, and fudge; or Nutter Butter ice cream with chocolate chips, Kit Kat pieces, and yellow cake chunks. (Yum!) Oh, and said flavors were created by Wish Kids at the Make-A-Wish Foundation. (Aw.)
Their site and store locater seems to have imploded this afternoon, probably due to insane amounts of traffic, but there are two SF locations: downtown (119 Ellis) and Fisherman's Wharf (2800 Leavenworth). Read more about it here.