The observation of minor planets is one of the main activities of my observatory.
In Switzerland less than half a dozen of amateurs are involved in the astrometry of minor planets. In year 1960 the astronomer Paul Wild discovered 97 minor planets and 7 comets during his photographic search of supernovae.
Here you can find some statistics of the positional measurements done in Gnosca. A list of the measurements taken on Near Earth Objects is here. This list counts 1521 positions (updated Jan 2011).