If you turn on the Xscreensaver module called Sonar while you're running a packet monitoring application (such as TCPdump), people are less likely to think you're doing anything shady, because "Only hacker tools don't have GUIs." Always hack your shell's personal configuration file (~/.bash_profile, for example) to change your shellprompt if you use GNU screen. That way you can tell what shells you've left open are single-access shells and which shells are multiplexed through a single connection with screen. It can get confusing sometimes. Because a shell run inside a GNU screen metaterminal sets an environment variable called $WINDOW, you …