http://docs.python.org/3.0/library/itertools.html says:

> The tools also work well with the high-speed functions in the operator
module. For example, the plus-operator can be mapped across two vectors
to form an efficient dot-product: sum(map(operator.add, vector1, vector2)).

I think there are two problems here.

1. I think this should read: "the multiplication operator ...
sum(map(operator.mul, vector1, vector2))."

2. This example has nothing to do with itertools! (At 3.n, map is a
built in function)

Fixed.  See r70317.