i like this idea..! I am planning to open source my CAPTCHA research if any one interested please contact me ..! you can find my research on http://dndcaptcha.blogspot.com/2010/04/textareaid.html

You can find presentation of the same concept here: http://www.slideshare.net/desaiguddu/drag-and-drop-captcha-a...

If anyone of you are researching or preparing Survey presentation or educational research on CAPTCHA feel free to use the content from the presentation.