Best Idea for a CAPTCHA ever

O’Reilly editor Brian Sawyer just sent a link to Mark Pilgrim’s new video blog with the headline: Best Idea for a CAPTCHA ever. Mark wrote: “I need to implement some sort of CAPTCHA based on Strunk & White. If you can’t tell me the difference between ‘continual’ and ‘continuous,’ I don’t want to talk to you.” OK. Maybe this is mostly for editing wonks.