Aren't friends great? Not the ones who force you into late night car park sessions drinking Mickey Finns out the bottle; no, the ones who inspire you to higher realms of consciousness and art. This exhibition takes two of the 20th century's finest artists and explores an unlikely friendship. Salvador Dali, the painter who mastered surrealism and absurdity, was good pals with Marcel Duchamp, famed for his work with cubism and the readymade. At first glance they don't have too much in common, but first glances can be pretty misleading. This big show puts two of the 20th century's biggest artists together and explores a seemingly unlikely friendship that impacted both's work, through themes such as eroticism, language and games. And a big bit of humour too. This features 80 paintings, sculptures, readymades, photos, drawings and films that reflect on their shared attitude to art and life. We also hear there's going to be some pretty graphic material which should give you some rare titillation at the Royal Academy.