Again not a long post, but never the less, hopefully something useful;
Recently I found a piece of software which extends the IMF somewhat. It gives the ability to do Whitelisting and Blacklisting, Adjust SCLs by Keyword, Reroute mail to a mailbox or PF (a quaretine area), Strip attachments and much more.
To find out more about this software check out the website here:
Overall, I personally find that the outsourced solution for Spam management (Exchange Hosted Services, MessageLabs, Postini etc) is the best/easiest solution but if you have no choice (or funds) for such a solution then the software above should help. (Note it isn’t free but is not at all expensive)