After the whole RIP drama, tr.im is back up! tr.im has been my favorite URL shortner, but not any more. I do not trust them, they can close down anytime (maybe next week) and come back up next month. Or even add Advertisements to URL redirects. So, you may not be sure how long your URL is going to be good. I do not trust them. I am using TinyURL at the moment.
Anyways, this was just for the information.
Happy trimming!