Harvesting wind energy used to be limited to large conventional wind turbines, until Lucien Gambarota invented micro-wind turbines for private use called Motorwind. The turbines are small (25 cm or about 10 inch in diameter) and can generate energy with wind speeds as low as 2 m/s.
Link - via Instituto Futurista and Inhabitat
Those kind of small wheels have been seen on pleasure boats for ages. Not that neat, sorry.