Captcha for anonymous/guest posting?

Hi,

I'm the web developer at a college in MN and Web Wiz is at the top of the list for a hosted BB solution.  The only feature that I don't see that we need is CAPTCHA for anonymous or guest posts.  I see that there's CAPTCHA for creating an account, but haven't seen any mention of it being used for anonymous posting.  If this is possible, I'll be ordering up a Business Community Hosting package.  We're meeting about this project tomorrow, so the someone can respond, the better. 

Thank You so much,

John