You've seen this one before, maybe. I'm still moving some of the old content over to the new site, so we'll have it all in one location.
By the way, doing this is unnecessary and adds a level of security risk. If you can login as root, so can't someone else. But, then again, there's already sudo and anyone with physical access to your computer could pretty much own your computer.
How To: Graphically Login as Root in Ubuntu • Linux Tips
In this article, I'm going to show you how to graphically login as root in Ubuntu. This is a generally a terrible idea and you should not do this.
linux-tips.us
By the way, doing this is unnecessary and adds a level of security risk. If you can login as root, so can't someone else. But, then again, there's already sudo and anyone with physical access to your computer could pretty much own your computer.