Much better solution

module GravatarHelper
# Returns a Gravatar URL associated with the email parameter.
def gravatar_url(email,gravatar_options={})

# Default highest rating.
# Rating can be one of G, PG, R X.
# If set to nil, the Gravatar default of X will be used.
gravatar_options[:rating] ||= nil

# Default size of the image.
# If set to nil, the Gravatar default size of 80px will be used.
gravatar_options[:size] ||= nil

# Default image url to be used when no gravatar is found
# or when an image exceeds the rating parameter.
gravatar_options[:default] ||= ‘http://localhost:3000/images/gravatar-80.png’

# Build the Gravatar url.
grav_url = ‘http://www.gravatar.com/avatar.php?’
grav_url << “gravatar_id=#{Digest::MD5.new.update(email)}”
grav_url << “&rating=#{gravatar_options[:rating]}” if gravatar_options[:rating]
grav_url << “&size=#{gravatar_options[:size]}” if gravatar_options[:size]
grav_url << “&default=#{gravatar_options[:default]}” if gravatar_options[:default]
return grav_url
end

end