I forgot to mention the three or four cherry trees at the junction of Stockport rd & Station rd. I've seen people picking the fruit. I've tried them myself but they seemed pretty sour to me. Maybe, given enough sugar they might become edible.
Once again, I'm a bit out of date with this thread.
Sour varieties of cherries are very good for making liqueur. Dead easy. The best recipe for this is in Jane Grigson's "Good Food" (Still in print, I think, but I got my replacement for my original copy, which fell apart, from that site named after a big river).
The book also has a delicious recipe for cassis, using blackcurrants and brandy - Kir Royale, anyone?
I'm experimenting with the recipe for Eau de Vie de Poire at the moment. Just laid it down for Christmas.
Perhaps we could set up a sort of non-allotment society for foragers and users-up of excess fruit and veg?