itsyourworld,
You can use a Grass Valley ADVC110 to take your camera's composite output and input to the MacBook via FireWire. Please note, this solution is only for standard def. If you have a powerful laptop an (i7 CPU recommended) you can use the H.264 Pro Recorder to input to the laptop via USB 2.0 to stream in HD.
The H.264 Pro Recorder and some other high quality laptop encoding solutions can be found in our store, at the following URL:
http://store.livestream.com/collecti...aptop-encoding