In one embodiment, an apparatus comprises a mount, a housing, and a sensor. The mount is adapted to be disposed at least partially underneath a shoelace of a shoe. The housing is configured and arranged to be placed in at least first and second states in relation to the mount, wherein in the first state...http://www.google.de/patents/US7200517?utm_source=gb-gplus-sharePatent US7200517 - Monitoring activity of a user in locomotion on foot
