YSK of togethersmile.com, a free, anonymous photography website where users upload a simple picture of themselves smiling, to give another person a reason to smile today.
from /r/YouShouldKnow
togethersmile.com的YSK，一個免費的匿名攝影網站，用戶上傳自己微笑的簡單照片，給另一個人一個今天微笑的理由。