I was in the process of setting each of the toggle interface buttons along the top to F1 through F8, and looked over the keybinding list very careful about 5 or 6 times, but I didn't see any options for toggling the messages panel. This is annoying because well, I have all the other keys set, but F4 currently isn't set to anything because the option simply isn't there! It should be a pretty simple thing to implement, in theory.

Also worth mentioning would perhaps be the Energy Depot