Latin teachers always seem to be in search of ways to help their students remember all those declensions and conjugations.
David Pelligrino has a collection of Latin Teaching Songs, covering noun declensions, prepositions, personal endings, intransitive verbs, a plethora of pronouns and question words. Especially noteworthy is the Preposition Song (sung to the melody of Ode to Joy by Beethoven), but they are all fun!
Magistra Mattingly has her students Sing Their Way Through Latin Grammar with a songs set to the tunes of the opening themes to Gilligan's Island and the Beverly Hillbillies.
Nota bene: The aforementioned sites include lyrics only.
Don't forget about the Endless Noun Ending Song, which is available in MP3 format, for listening to online.