Router peer access-list creating scripts

Hi, Does anyone know of any scripts which will help us keep the filters on our peering routers (Ciscos) up to date, so we only allow them to announce those routes to us that they have registered with one of the routing registries? Keeping these filter up to date manually is a pain, particularly where a peer announces several customer AS numbers to us. We'd rather filter than just leave ourselves open to our peers annoucing any old garbage to us. What does everyone else do? Wookie