From the Apple site:
- Stereo speakers with subwoofers
- Omnidirectional microphone (located under left speaker grille)
- Audio line in minijack (digital/analog)
- Audio line out/headphone minijack (digital/analog)
- Support for Apple iPhone headset with microphone"
To use the ports in a digital setup you need an Optical-mini to Toslink cable
Now that most DAWs including Protools allow you to use any any audio interface, this is a no brainer.
You can connect your laptop to the A/D-D/A converter of your choice and get the best quality sound. The Macbook's ports accept sample rates from 44.1khz to 192khz.
If you already own Toslink cables then just purchase the adapters ($2) at Amazon:
You can also use this cable to connect to your home stereo or surround sound system.
Thanks to Mikey Bassie @MikeyBassie for bringing this to my attention.