In its traitional sense a street party is just what it says: a party taking place on a road. In Britain, these have historically been held to commemorate momentous events, such as VE Day or the Queen's Silver Jubilee. These are usually jovial, community affairs where neighbours can meet, often for the first time, in their traffic-free streets. They successfully counter the anonymity of our mobile, diverse lives. A group called Streets Alive promotes them to become a regular part of British culture and they have a useful website resource.