Tr.im is in the process of being terminated by Nambu Networks, its developer. They've requested developers to begin removing their service from applications and replacing it with other options.
Personally, I love tr.im and wish that it wouldn't die (I'm working on a blog post about the situation), but for now I've switched my personal shortening to SnipURL, which offers sn.im, cl.lk, and st.im as domain options.
Within Shorten2Ping, however, I've had to fall back to my Bit.ly account. It would be nice if j.mp was supported, as that's shorter even than tr.im, but I really like SnipURL too. Would you consider replacing the tr.im option with SnipURL? (API docs)