exporting vcards from rails

Derek Neighbors wrote:

i'm doing a site for someone that has a form set up to collect contact
information from the user. i installed the vpim gem and was hoping to
give my client a way to download all of the contact's information as a
vcard. using the examples, i was able to get it working in ruby,
but i'm
not quite sure how to generate and download a vcard on the fly.

has anyone done anything like that?

We are doing this using the SimplyRESTful stuff...

In the controller for example we have:

   def show
     respond_to do |format|
       format.html
       format.xml { render :xml => @contact.to_xml }
       format.vcf do
         send_data @contact.to_vcard, :filename => "#{@contact.id}.vcf",
           :type => 'text/directory'
       end
     end
   end

Using this technique gives me a server response with:

"uninitialized constant Mime::VCF"

I found several mime-type related files in the following directory:
/Library/Ruby/Gems/1.8/gems/actionpack-2.2.2/lib/action_controller/
mime_responds.rb
mime_type.rb
mime_types.rb

Is there a way to add the .vcf mime-type?