UNIX admins would know this, and perhaps many Linux admins would also know this, but do you know what the file /etc/motd does? It's output when you login via ssh and similar tools.
Some people like to embellish what is output with various terminal control characters to do things like enable/disable bold, underline and other special characters. One thing I don't recommend though, is to try to use colours, its just too non-portable. Here is an example of what you might see.
