I became interested in the Maori thanks to reading Jared Diamond's Guns, Germs and Steel - see the book on Amazon and the PBS GGS website.
I found this incredible video of a performance of a poi song, Poi - Ma Wai E by Ngati Rangiwewehi at a festival in 1996.
I'm trying to find out who arranged the song, what the lyrics are and what the translation is.