Rating documents

Hi In my project there is a necessity of allowing the users to rate documents. Say a rating scale from 1-5 will have to appear in each document (created using a template). Users can rate a document and an overall rating appears after calculating all the ratings. At present I did the whole thing using servlets. But is this the preferred way to do this in xwiki. Can this be done by making use of xwiki plugin or so, so that it will be useful for others also? Any hints ? Regards Roopesh