Rails 3 - upload files to public directory

I'm looking for a simple way to upload a file (an xml file) to the public directory of Rails 3. Once it's there I want to open it, parse the contents and delete the file after that.

Whenever I searched for file upload I encountered Paperclip. But I don't want to associate the file with an object. I just want to upload it. What's the easiest way to do this?