Gravatar Image Helper Function. Provide an email, it will return image_tag for corresponding gravatar. Pass in options hash as usual

Rails - Gravatar Image Helper

def gravatar_image(email, options = {})
  gravatar_url = "http://www.gravatar.com/avatar"
  gravatar_hash = Digest::MD5.hexdigest(email.downcase.strip)
  image_tag "#{gravatar_url}/#{gravatar_hash}", options
end