Common Spam Words -> Auto-Refuse

I modified WP slightly to add a new option, in the area of the Common Spamwords… basically to set whether or not to always refuse posts that contact any of the Common spam words set.
I wrote this because I found myself spammer with poker posts (as we all have, I’m sure), and wished those would just get ignored, rather than moderated.
Would anyone else find this useful? Is there already some hack that does this? Perhaps it’s already a feature, and I missed it?
If it’s useful to others, I’ll be happy to put together patches/instructions…