There are others (some even shorter), but I have some concerns about most of them. The main concern is whether or not the new link will be permanent.
TinyURL promises that the link will never expire.
Twitter has a popular one t.co however your links are owned by twitter, are supposed to be for twitter use only, and they expressly say the links may not last.
Google has their own service and also state they won’t expire: https://goo.gl/ however google has a history of adding and dropping services to meet their own needs.
Tr.im is another one. But it is owned by an advertising company, and I don’t trust them to maintain their links.
https://bitly.com/ is yet another – again it is designed and advertised as a marketing tool. In fact I believe almost all of the other URL shortening services are owned by for profit companies and so are less likely to maintain these links far into the future.