Using a notebook pc as a portable video /audio mixer

[Haopengyou]

This is a bit of a follow up to a question I had a couple of years ago. I work with orphans in China and often record the children in some kind of performance to help them enjoy their learning experience more. I also use the video for fund raising as well. I travel by train, bus, taxi and sometimes on the back of a motorcycle to get places so I cannot tote hundreds of pounds of equipment with me but I like to be able to show the students a nicer product than just "raw" video when I am finished.

Given the fact that most camcorders use digital media these days, it is possible/reasonable to plug the camcorder (or even a pair of camcorders) directly into a notebook and use the hard drive of the notebook to save the data, and to plug the microphones into the notebook as well? I would like to be able to have 2 tracks of video and 3 tracks of audio.

If this can be done, what is the oldest hardware (pc and/or mac) that would make this happen?