If you have a printer connected to your parallel port in Linux, you can use the command "cat /dev/urandom > /dev/lp0" to send random data to your printer. This can result in some very strange looking characters in different styles and fonts, often written on top of each other, and often looks overall very cool =). This same idea can be used with the sound card (/dev/dsp). Both of these are great ways to confuse people near your computer remotely through telnet.