I hate those wretched CAPTCHA things. Too hard to read, and they don’t do a good job anyway.
If you have a website where people can sign on to some service, and you need to be able to distinguish between people and robots, consider HIVE instead.
You can try it here.
One of the challenges was not clear to me. At the moment it may be too USA centred (products, seasons, etc) to be applicable to wordwide users, but it is still in development.
In the meantime, it’s easy, it works, and it’s fun instead of frustrating.
I wish them every success.