BarnOwl is a curses-based instant messaging client supporting the Jabber, IRC, AIM, and Zephyr protocols. It is designed to be easily extensible through Perl plug-in modules, and much of the core functionality is provided by such modules.
reptyr is a utility for taking an existing running program and attaching it to a new terminal. Started a long-running process over SSH, but have to leave and don't want to interrupt it? Just start a screen, use reptyr to grab it, and then kill the SSH session and head on home.