Millions of pounds-worth of damage have been inflicted on the city, with destruction and looting in all points of the compass (map). Nearly all London communities have been affected in some way. The law-abiding majority need to reclaim the streets, and that begins by tidying up. We must all become Wombles.
The tools of communication which helped the rioters organise can also be turned towards remedy. A Twitter account and website have already been set up. Follow @riotcleanup (and the #riotcleanup hashtag). The account already has over 12,000 followers and is gaining momentum. The full and developing list of cleanup sites can be found here. But, basically, if your high street's been hit, just head out and see what you can do.
UPDATE: A new hashtag, #riotwombles, has emerged for anyone helping with cleanup.
If you have information for the police, you're encouraged to phone the new 101 number rather than 999, unless it's a true emergency.