I remember a long, long time ago, in a galaxy far, far away, I played around with setting up custom DOS prompts. Memories of Ansi.sys and custom ANSI art come streaming into my brain...
Forget all that. On CentOS, these two commands will install the Z Shell and Oh-My-Zsh
yum install zsh
sh -c "$(wget https://raw.github.com/robbyrussell/oh-my-zsh/master/tools/install.sh -O -)"
Tab allows you to visualize potential paths, running processes, ls without hitting enter, and other awesomeness.
There are one or two Themes and Plugins available.
Some laundry lists, tricks and cheat sheets.
If you're running Windows, 720MB of Babun will get you Zsh among other things...