clean up taxonomy

hello

is it possible to check cron.php driven for orphaned terms and delete them out of the box?
did somebody already configured something like this?
if not: has somebody an idea which would be the ideal locations (actions, triggers,conditions) where i have to write a short php snippet?

thanks momper

Is there a module that goes about cleaning up "orphan" free tags, i.e. free tags that are not associated with any nodes?

In general, can you share a tip to searching for modules?

Thanks.