there is already a programme to “check relations”. It can be found here: http://wiki.openstreetmap.org/wiki/Relation_Check

You can downlaod the source (in Perl) or ask the maker to run the check on an area you are interested in. Germany and The Netherlands are already on a regular basis evaluated.

If you are able to run the Perl programme yourself, it would be appreciated if you share the results on a wiki page.

Success, Hugo