What a ridiculously good idea. The RCA Secret is an annual exhibition and sale of 1,000 original postcard-sized artworks donated by reknown artists, designers, illustrators and current post-graduate students of the RCA. Each postcard is displayed anonymously, with the artist's signature on the back, so the artists are not revealed until after the cards are purchased. This year, contributing artists include Yoko Ono, Tracey Emin, Manolo Blahnik and Sir Paul Smith, to name but a few. At £45 a piece (and with a Peter Doig postcard, bought in 2000, later selling for £42,000), Londoners, I'd be camping out for this one.