Plans are afoot to power a new building in Sweden entirely with the heat generated by moving bodies in Stockholm Central Station, the biggest train station in the Nordic region. How will it work? From Inhabitat:

Quite simply, the heat generated [by human bodies] will warm up water running through pipes which will be installed in the station. The water will be pumped to the new building and used to heat the spaces inside. "This is old technology, but used in a new way. It's just pipes, water and pumps, but we haven't heard of anyone else using this technology in this way before," said Karl Sundholm leader for the new project.

Human Body Heat to Heat Green Building in Sweden [Inhabitat]