This is the friendliest console-based-installer I've ever used:

I love the way it keeps the stress down by saying stuff like: "But don't worry, this installer will tell you how to ...". Very friendly indeed.

It's for Phusion Passenger - a module for hosting Ruby on Rails apps in Apache. Credit to the makers. It makes hosting Rails totally simple. I just switched from using modproxybalancer and mongrel, and it's a walk in t' park so far.