PPAs on Launchpad are an amazing way to get the latest crack builds, which is useful if you track or contribute to an upstream project, or test new code to see if it resolves a problem. That’s what I’ve been doing this week – I  installed the latest Xorg crack on top of a karmic beta install.

If you visit that last link, you’ll find a description of how to install and use a package called ppa-purge, which will revert the PPA settings and restore the packages to the distro versions. This makes it much easier to restore the system, or even to bounce between the distro and bleeding edge versions and see what changed.