It has always annoyed me as a user when having to strain my eyesight and having to type weird letters or numbers in order to prove I am a human. The practice is known as ‘captcha’ and dates back a while now. Regretfully, nothing much has changed aside from the ability of the bots to OCR better – we still need to read some obtuse characters.
This is why I wrote a javascript mootools captcha class called hOOmanTest – making the whole ‘prove you are not a bot’ a lot easier to stomach. Regretfully, it has no degradation as it relies on drag and drop, but you can use reCaptcha inside your target div as the fallback and have the class apply an .empty() before populating it, providing the upper layer.
*edit*: I really do hope it helps somebody, here is the first site that uses it out there–in a quotation webform on the cleaning 4u site, click the free quote banner to view.
I have implemented this fantastic captcha on my site here: http://www.roberttilt.name . My only reservation is that I cannot get it working in IE. I have all the necessary dependencies as it works in moz and webkit, so I’m in a conundrum as for the break.
Your version works great in IE 7+8, were there any tweaks you had to do that aren’t written in the main class?