I have done the following steps:

Added to gemfile:

gem "recaptcha"

Added to config/initializers/recaptcha.rb

Recaptcha.configure do |config|
  config.public_key  = 'MyKeyHere'
  config.private_key = 'MyKeyHere'
end

Added to view:

= raw recaptcha_tags

Ran: bundle install

...then restarted server. The result?

undefined local variable or method `recaptcha_tags' for #<#<Class:0x1053baaa0>:0x1053b69c8>
ruby-on-rails rubygems ruby-on-rails-3 recaptcha
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