title: How to directly access MongoDB API from Mongoid?
body: <p>I'd like to use the <a href="http://www.mongodb.org/display/DOCS/Updating#Updating-%24addToSet" rel="noreferrer">addToSet</a> method of MongoDB, but Mongoid doesn't currently support this yet. Is there a way of directly accessing the MongoDB driver from my Rails model?  </p>