When the FitFlop launched in London in 2007 it became an instant hit and sold 18,000 pairs in three days. These sporty go-anywhere sandals - the brainchild of Bliss founder Marcia Kilgore and Dr Dave Cook - are engineered to tone and trim your legs as you walk. Described as 'a flip flop with a built-in gym,' fans of the innovative fitness footwear include Hollywood style-setter Mischa Barton. This limited edition 'Aurelia' sandal is already touted by Sunday Times Style as this summer's must have shoe. Available online from early August.