I often find myself looking for a Unix or Linux command in the shell, not quite sure which command I want, but knowing the rough area or purpose of what I'm trying to do. For example, I know it has to do with listing or manipulating processes, or adjusting the way sudo works.
I just stumbled upon a great list of Unix commands, the Unix Toolbox, which is organized exactly for my scenario. w00t! Bookmark it.
Thanks for Francois Schiettecatte for the link.