I'm trying to find an inexpensive means of auditing printer usage. I like
the built-in auditing within NDPS. However, this method still leaves us
with bit of an accounting issue. To ensure someone hasn't printed while
logged in with someone else's account I would think a solution might be to
simply require certain users to authenticate for each print job
submitted...which would mean it didn't matter if a user forgot to log
off...the only way you could be billed for jobs you didn't submit was if
you handed out your username and password.

I don't see iPrint/NDPS doing this natively but thought I'd ask to be