Rather than dealing with an outside service for spam filtering, I'm working on the idea of a simple question to block spam. The comment form asks a simple question that a spambot might not know. It may require more work, but some users of Radiant may find things difficult enough without needing to go to Akismet or Mollom for spam filtering. Yes, I know that's a simple task, but for some just the idea of yet another thing to do gives them pause.
So with this post, here's my test of the spam_answer_tag. It's easy to use: you simply add
What color is a stop sign? < r:spam_answer_tag answer="red" />
I'll certainly be doing more work on the extension to clean things up, but I felt that it needed at least a simple CAPTCHA type of option built-in without all the downsides of generated imagery CAPTCHA.
Let me know what you think!
UPDATE: after reading Adam's comment about the number of questions I realized that you can easily provide your own list of options with Radius tags that are already a part of Radiant. Just use