MythTVOS 2008 is based on MiniMe 2008 and has MythTV and all plugins installed and (pre)configured.
Just boot from the livecd, select your TV / SAT / CABLE card and scan for channels…
In the future, its developement is targetted to provide both a remaster download and a metapackage distribution to allow the creation of a full MythTV setup from a regular PCLinuxOS installed system.

If installing to disk: Near end of installation you will be asked to provide a new root password. Do so. Next you'll be asked to enter a username.. Just hit Done here without entering a user.. The default mythtv user and preconfigured settings will be installed..
Have Fun!

• MythTVOS "Gnome" torrent (tpb) - 1.2GB (gnome desktop)
  
• MythTVOS-2008 "MiniMe" torrent (LT) - 464MB (kde desktop)

MythTvOS developement, test and suport Forums (login required to post)

For general MythTV information refer mythtv.org or to the wikipedia related article