3rd January 2006, 10:40 AM
Speaking as someone who has run an SMR, one thing that metal detectorists could help with is finding post medieval mills (water or wind) which have no accurate grid reference. The same goes for any small rural industrial sites, though there would be no real gain for the MD other than knowing they found the site as all that there is likely to be is a scatter of nails in the ploughsoil.