(Already know how to set up a repository? Skip to the PPA.)
Ubuntu Repository
To start, open System > Administration > Software Sources. On the Third-Party Software tab, click the Add button. Find your Ubuntu version below, and then copy the listed line into the APT Line text box.
8.04 Hardy Heron
deb http://ppa.launchpad.net/xeiso/ppa/ubuntu hardy main
8.10 Intrepid Ibex
deb http://ppa.launchpad.net/xeiso/ppa/ubuntu intrepid main
Click Add Source, then close the window. Be sure to hit Reload to refresh your package information.
Installing
Once you have the repository added, simply install the xeiso package. You can do this via apt-get, aptitude, or use Synaptic. Alternatively, click the link below to install automatically: