bit.ly is the most famous URL shortener service. BTW, bit.ly also accept private-URL:

http://bit.ly/424F8W -> http://localhost/
http://bit.ly/lERx -> http://127.0.0.1/
http://bit.ly/EQw4S -> ftp://127.0.0.1/

If your intranet have foobar.intranet domain, it is also applicable:

http://bit.ly/cJAIZi -> http://foobar.intranet/
http://bit.ly/bBjLVl -> http://foobar.intranet/some/what/path

But I think it is not good idea for using bit.ly to intranet. Because private intranet address data is transmitted over public internet.