SuperPoke is a Facebook application that lets a user 'perform actions' to their Facebook friends. Initially made as a joke, it is best known for starting the "throw a sheep at" meme.
From what is understood, SuperPoke was created as follows. The creators had gone out for dinner, at which time they decided to come up with a Facebook application that let users reach out to their friends in a silly but creative way. Later that night with the idea still fresh in their head, Nikil Gandhy taught Jonathan Hsu and Will Liu(?) how to code. Gandhy then proceeded to stay up all night and finished the first version of SuperPoke; V1 was ready for launch. After the first day, SuperPoke had 1000 users. When SuperPoke hit about 20,000 users, Dreamhost shut them down for using too much of the shared servers resources. Gandhy then called Aaron Wadler at Viddyou and borrowed servers from him to get SuperPoke by. SuperPoke added a thank you and link to Viddyou, which caused confusion for the media. http://news.cnet.com/8301-17939_109-9729008-2.html
Within a few weeks, SuperPoke had hit 1 million users and was rapidly growing. Keith Rabois of Slide reached out in an offer to acquire SuperPoke, and several weeks later the acquisition was complete.