Over here Randy asked a really good question: Why does every comment require a Captcha response (that's the little thingy where you type text that's hard for spam robots to read)?
Here's why ... some comment spammers will create accounts manually (easily answering the Captcha) and only THEN turn their robots loose on comment forms that don't have Captcha. Those robots work fast and, before you know it, we've got tons of spam comments that need to be deleted. So that's why we require the Captcha for every comment.
But there are some alternatives. One that we've considered selectively shows the Captcha depending on the "reputation" of the commenter (i.e. comment history) and text analysis of their comment. It's free/cheap, but would require some work to implement.
It's times like this that I love to turn to you, the Network community!
What do you think ... how annoying is the Captcha? Does it deter you — even a bit — from posting a comment? What about new users?