I have converted some wav files to ogg files in people putty theatre.
From what i understand there are different types of ogg programs.
One is like what Art said, similar to mp3 which is a compression program (correct me if i am wrong) the other is similar but, it also allows other data to be imbeded in it like the lip sync.
Everyone must have the Haptek guide, in it it talks about this.
They use a program called, or from, i think Lipsinc, i tried to go there but could not find it.
Anyhow getting back to the wavs i converted,
A wav of speech when converted to ogg and played back in the player came up great.
A wav of a song when converted = No Way
It lip syncs to every sound including the music.
I hope this is of some help.
Neil.