I think marked tracks are recorded on the player's scratch partition, /dev/hda3. Assuming there's room, this could probably be used for anything else the player wants to use it for, including favorite visuals, but that's not how it's done right now. As of now, the favorites are stored in /empeg/var/config.ini which is on the root partition. If the visuals were stored on the dynamic partition, along with EQ settings, etc, you could add/remove them at will. Not sure why config.ini was chosen instead.