Putting line-breaks in the (Mountain) Lion lock screen message
Solution 1:
Press Ctrl+Enter for a new line (or Option+Enter, which seems to work as well).
Solution 2:
It actually is. You can't do it directly from System Preferences - you can do it using TextEdit. Just type your lock screen message into TextEdit and copy-paste into the text box in System Preferences. If you use more than three lines, then a scroll bar appears and everything looks all buggy and ugly. Three lines or less works perfectly - in fact, I have three lines right now! (Third line blacked out as it contains my email address)
