Here is a list of useful utilities presented at the roundtable meeting:

cd -	change to last working directory
popd / pushd	directory stack tool
screen	terminal multiplexer
xargs	command-line argument manipulator; workaround for maximum argument list lengths
reverse-i-search	bash builtin to search command history
nmap	network mapping and probing tool
zenmap	GUI for nmap
aptitude	ncurses-based frontend for apt (Debian/Ubuntu)
apt-file	tool for searching packages for certain files (Debian/Ubuntu)
xrandr	screen rotation and resolution changing utility
pv	pipe-viewing tool: watch how much data is passing through a pipe
htop	improved, interactive 'top' for process management
wicd	wireless connection manager
genius	general purpose calculator utility
dc	RPN (reverse Polish notation) calculator utility
bc	very simple calculator utility, useful in scripting
less -S	chop lines, allowing side-scrolling for long lines
most	advanced pager, like 'less' and 'more'
grep --color=auto	when searching, colorize matches (default on Gentoo)
impressive	similar to Mac's Keynote (used to be called keyjnote)
clutter	C++ presentation framework