RCA Secret 2008 

RCA Secret, now in its 15th year is an annual contemporary art exhibition and fundraising sale consisting of around 2,000 original postcard-sized artworks. All made and donated by professional artists, designers and illustrators, plus up-and-coming graduates from the College. The cards are sold to the public at a one-day sale on 22 November, with every postcard costing just £40, regardless of whether it has been made by a famous name or a young art student. What’s the Secret? Each postcard is signed on the back, so buyers do not know the identity of the artist until they have made their purchase.
http://www.rca.ac.uk/secret