reCAPTCHA

I’m not really a fan of CAPTCHAs as all too often they’re inaccessible to disabled users, but I must admit to being impressed by the ingenuity of reCAPTCHA. They provide plugins for most popular web software for you to use as you would normally, but the twist is that each correctly supplied word helps to digitise books by using human input to convert the scanned type; a task that people are good at but computers find difficult. Clever!