After having these issues:
How do I fix broken installation?

... I've decided to reinstall Ubuntu (11.04). I need to do so from the command line. And, while I am reinstalling to clean up and solve some general, confusing problems, I'd still prefer to keep preferences like Keyboard Shortcuts if possible. Is there some magic wand to reinstall like there was with upgrading from 10.10 to 11.04? If I have to back things up on my own, what's a good way to do so from the command line? Are there any other tips you might give me based on the problem I described in the above thread? Finally, do keep in mind that Ubuntu is one of multiple partitions on my machine.

I suppose the main question here is, what is the easiest way to reinstall from the command line? I obviously have my own particular sub-questions here, but, for the sake of the community, a generalized answer will, at least, earn you an up vote from me. I suppose the ideal answer would have one big line with the simple command at the top, and details for my situation somewhere under that.