Rockbox, the open source jukebox firmware, just released its latest version, version 3.0. Rockbox adds WMA, Ogg and Flac support for your iPod (and other portable music players) and not to forget, DOOM! Yes, that classic 3D first person shooter game. For a complete list of features, check out this page.
So, if you are sick and tired of your iPod (insert your favorite portable music player here) and its closed nature, I suggest trying out Rockbox – it definitely makes your iPod rock!