Playing around with MotionCAPTCHA
Looking through my RSS feeds I saw a post about a new form of CAPTCHA using mouse movements instead of blurred text like normal CAPTCHA services. Considering I don't have such post validation, I decided to try it out.
MotionCAPTCHA uses the HTML5 <canvas> element and jQuery to render the box and read mouse movements. The files involved only consist of a js file, css file, and a jpg containing the patterns, and requires no back-end knowledge. All you need to do is link the css file to you head, change your action to '#' in your form and have your action be a hidden element, add the canvas element and disable the submit button. Then all you need to do is link jQuery and the js file below your form, and add a call below that using jQuery.
MotionCAPTCHA is in v0.2 right now and does not support touchscreen controls, but they are working on that for future versions. Until then, the current version works fine for current browsers.
You can download the code and view instructions at the Joss Crowcroft's website.