Long on the cutting edge of CAPTCHA development, Google's reCAPTCHA project has released a new and ironic version of the service which will make life easier for users.
Most of the time, users should no longer have to parse and retype fuzzy numbers or letters. All they have to do is check a box, agreeing that "I'm not a robot." See an example using early adopter SnapChat nearby.
Google says that they can get away with this for two main reasons: bots have gotten very good at parsing even very difficult characters. Second, Google has developed the ability to look at behavioral characteristics of the connection to determine, with a high degree of accuracy, whether the user is a human or a bot.
In cases where the risk analysis engine thinks the user may be a bot, it presents a conventional CAPTCHA, at least for now.
The same internal changes to the engine allow Google to include new, more mobile-friendly CAPTCHAs. See examples below: