I read about this adidas convertible jacket in the new issue of Health and Fitness. It costs £65 but can be worn as a cropped top, a vest or a full jacket as shown. This will definitely go on my wish-list I think the colour and cinched  waist are nice details too. 

http://shop.adidas.co.uk/product/GM060/P93309/Sports/Women's-adiSTAR-Convertible-Wind-Jacket/detail.jsf?selectedProductViewIndex=0&selectedQuantity=1