Less Captcha creates a user friendly, bot unfriendly image CAPTCHA alternative

== In the model

class User < ActiveRecord::Base
  validates_captcha
end

== In the view

<p>
  Unless you are a bot answer this question: <%= captcha_display %>
</p>
<p>
  <%= captcha_field("user") %>
</p>

== Generated HTML

<p>
  Unless you are a bot answer this question: <span class='less_captcha_challenge'>What is 4 + 7?</span>
</p>
<p>
  <input type="text" name="entry[captcha]" />
  <input type="hidden" name="entry[captcha_answer]" value="e43b21e80194c61f30930a442f2c19de6fe74f8c" />
</p>