A couple of great community initiatives worth highlighting:
Streetbank: what Dave Walker describes sounds like the way neighbourhoods used to operate (maybe some still do?), but 'Streetbank' sounds a bit funkier than 'organised sharing'. It's a local website for lending things to one another, so slightly different from Freecycle, which is a local website for giving things away instead of throwing them away.
Cardiff Food Bank set up a year ago to provide food to people who'd otherwise go without (a recent visiting speaker told us of a home visit to a family where all the food in the house was a tub of margarine and a bottle of ketchup). There's something similar in Yeovil, the Lords Larder, which works by collecting food from collection points around the town (churches, businesses etc. ) and then giving out food parcels to local households (nearly 2000 people last year). The Cardiff setup does something similar, but also goes straight to the supermarkets, and quite succesfully too.