If you need short URL service integration with your site - this service provides API which works with GET method.
Simpliest method is GET: all you need is to send query string with URL encoded like
http://etiny.info/api.php?url=http://www.google.ro
As answer you'll have plain text string/s with shorten URL - something like
http://etiny.info/fneck
GET variables allowed:
go - either "twitter" or "pownce" - redirects user to post forms on Twitter.com or Pownce.com with new short link filled in forms automatically.