Amazon.com in 1995
Thefacebook home page (February 2004)
YouTube, beta test homepage (retrieved April 28, 2005). The original idea for YouTube was a video version of an online dating service.
BackRub, the Google prototype (March 1996, http://backrub.stanford.edu/backrub.html)
Google home page demo (1997, http://backrub.stanford.edu)
Twitter, a sketch by Jack Dorsey (2001). His project, called "Stat.us", dated back to 2000.
Twitter in March 2006, used as an internal service for Odeo employee