I started resetting my website about 10am this morning. Then I was interrupted before I was able to install anything to perform human versus robot validation on my forms. In about 12 hours, I received 29 bogus user registrations from disposible emails.
My phone dinged and boinged all night long while I was at work until a few minutes ago when I set up "Are You A Human" on my website. It's a more fun alternative to the squiggly letters.
Here's a website for their demo, http://areyouahuman.com/demo/. Enjoy!
You can also read a nice article about it at http://venturebeat.com/2012/09/14/are-you-a-human-captcha/