KeepRight offers data consistency check routines for openstreetmap.org
openstreetmap.org (OSM) provides a wiki-style means of creating a world-wide street map where everybody is encouraged to contribute. This is a collection of scripts that will examine part of the OSM database and try to find errors that should be corrected by users. As a result you get ugly lists of errors and are invited to correct them.
These details are provided for information only. No information here is legal advice and should not be used as such.