The website of the Trowbridge and District Metal Detecting Club ("Saving and preserving Wiltshire's history" - should read "pocketing Wiltshire's history") has a "game" which shows just how moronic metal detecting is, note that this one is done on grassland (check out the Code of Practice for Responsible metal detecting, not the "shut ther gate" NCMD one)
If you cannot get out in the fields then why not detect virtually? turn your speakers on!A good reason why not to detect virtually is that it's a waste of time. You take an artefact out of a little hole, cannot see where it lay and with what, and put it into a new 'context', a tray with little compartments for it, and you 'score points'. Whoopee.