I carry the unixtoolbox(http://cb.vu/unixtoolbox.xhtml) with me as a quick reference cheat sheet everywhere, the pdf is on all my devices, it has pretty much all the tools I need for my CLIing. Check it out, chances are you will find something new and interesting you can start using. I work with CLI all day, some tools that make my life a lot easier: tmux, Vi, sed, grep, ssh aliases