First, let me say that Spam Free WordPress is one of the best plugins I have ever used. Simply put, it does it's job. It's kept our site (and our admins) from having to deal with thousands of spam posts in the last few months, and we couldn't be happier. Would that every paid plugin did as good as job as this free one!
I'm wondering if it would be possible to provide a user text area, so that sites can impart info to would-be commenters. For instance, we're finding (with our demographic) that we're getting a TON of unsophisticated surfers who run into problems posting comments because of overly-sensitive security software and browsers with everything shut off. We spend a fair amount of time instructing noobs everyday, and it would be very helpful to be able to tell them what minimal requirements are necessary to comment.
Also, we get complaints that the password field needs to be filled manually (i.e. they can't copy-and-paste). I'm not sure what's causing this (technically), but it's frustrating to have to manually type in a complex password. Perhaps the workaround would be a shorter password?
Anyway, thank you for your great work! :-)