How can I unshorten a URL?

Question

I want to be able to take a shortened or non-shortened URL and return its un-shortened form. How can I make a python program to do this?

Additional Clarification:

Answer 1

Open the url and see what it resolves to:

>>> import urllib2
>>> a = urllib2.urlopen('http://bit.ly/cXEInp')
>>> print a.url
http://www.flickr.com/photos/26432908@N00/346615997/sizes/l/
>>> a = urllib2.urlopen('http://google.com')
>>> print a.url
http://www.google.com/