Trillian is notorious for doing things like this:

So the window is off the screen, no way to drag it back. Did you know you can right click the item in the taskbar, select "move" and then use your arrow keys to bring it back down into a state where you can use your mouse? I never realized that the "move" feature on the context menu (right click) of an application in the taskbar allowed you to move the window with just the arrow keys. Very cool.