How do services like TinyURL or Metamark work?
Do they simply associate the tiny URL key with a [virtual?] web page which merely provide an "HTTP redirect" to the original URL? or is there more "magic" to it ?
[original wording] I often use URL shortening services like TinyURL, Metamark, and others, but every time I do, I wonder how these services work. Do they create a new file that will redirect to another page or do they use subdomains?