RFC: Example showing how to write a least-squares polynomial fit in Julia 

I have written a simple program which performs least squares fitting. This is meant to be a stand-alone example of how to use Juila to solve a simple, but not trivial mathematical problem. it is aimed at Julia beginners. I envision this could become a classroom example of how to use Julia.

This example follows the methods discussed on Wikipedia:
http://en.wikipedia.org/wiki/Linear_least_squares_%28mathematics%29