Currently PHPShortener supports the 7 most popular shortening services. It will convert a long URL into a short URL, and then decode a short URL to its long version.

Services:
- is.gd
- bit.ly
- tinyurl.com
- tr.im
- twurl.nl
- digg.com
- u.nu

Features:
- Easy to use
- Flexible, easy to extend with new services
- Auto detects the service in the URL to decode
- Tiny, but well written and commented.
- PHP5 / PHP4 compatible (although only tested in PHP5 so far)
- Works with cURL or fopen wrappers, without configuration.
- Decodes URLs by inspecting the redirection headers

Listed in Link Checking php scripts category