Logical Captcha takes advantage of the TextCaptcha.com service, which provides logic-based textual questions instead of distorted images or audio to validate that the entity registering is a real live human being, and not a spam bot. It will provide protection against false registrations and the dreaded spam comments, etc.
An example of such a question might be:
Question: 
Out of a truck, a lion, the color purple, and the number forty-two, which has a door?
Answer: 
truck
Textual logic-based captchas mean that your registration process will be accessible to everyone, including visually/hearing impaired visitors who use access technology to surf the web. It requires a free API key from <a href="http://TextCaptcha.com" rel="nofollow ugc">TextCaptcha.com</a>
This plugin was developed by Josh de Lioncourt of <a href="http://maccessibility.net" rel="nofollow ugc">the Mac-cessibility Network</a>, a site dedicated to blind and visually impaired users of the Mac OS X operating system, the iPhone OS, and other Apple Inc. products and services. Josh de Lioncourt, the Mac-cessibility Network, and related sites are not in anyway affiliated with TextCaptcha.com

Logical Captcha

Integrates a logic captcha to verify that the registrant is a human and not a spam bot instead of using distorted images or audio.

Jeff Sherk

Julien Laumond

This plugin has the following great features:
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Auto-login: When a new user registers, this will automatically log them in right away.
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Redirect: Choose the web page you want them to be redirected too after they register and are auto-logged in.
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Independent options to add Password field to new user registration form, so users can create their password during registration instead of having to wait for an email and clicking the link in the email.
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Independent options to add First Name field and/or Last Name field to registration form.
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Independent option to disable the annoying admin notification emails about new user registrations. User will still receive their email about how to setup their password.
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Independent option to disable the annoying admin notification emails about users lost/changed password. User will still receive their email about how to reset their password.
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</ul>

Auto Login New User After Registration

Automatically login new user right after they have registered. Add Password field to registration form. Disable admin notification emails of new user  …

Logical Captcha vs Auto Login New User After Registration