Footwear is provided with a series of removable insoles, each being adapted to be detachably installed to the outsole. The insoles have a wearing surface which conforms to the shape of the user's foot, the wearing surface of each insole being configured to accommodate a progressively larger foot size,...http://www.google.com/patents/US6092311?utm_source=gb-gplus-sharePatent US6092311 - Interlocking footwear insole replacement system
