Am I wrong or is there no function for this key combination?
My suggestion is to use it to obtain the last command or line entered regardless of which window it was entered in, so I don't need to remember which window I was doing commands in after I've switched through a few windows to chat, and I can just access the lines from the one I switched to.

Run this in an editbox: /!

and who says you don't learn something new every day! Thanks Zac
Any other suggestions for that key combo?