Multiple Audio Outputs without buying anything?

I would like to hook up 2 separate sets of speakers to my Macbook pro.

Is there any way to do this without buying any type of interface?
If not... what is the best interface for the price that will do exactly what I want?

 

I was thinking of that but I wanted to have each speaker set producing a different sound for music performances.
(Metromonome coming out of one speaker pair, and piano coming out of the other speaker pair) Is there any way to do that?

 

I guess so but I would want the metronome sound to be coming through a headphone and the piano sound coming out so everybody can hear and only I could hear the metronome.
I guess id need an audio interface for that aye? Anyone use a cheap one they'd recomend?

 

That's perfect! Thanks alot!