Another gotcha with for loops: scoping is a little weird.

    	xs := []int{1,2,3}
	for _, x := range xs {
		go func() {
			fmt.Println(x)
		}()
	}

That prints `3 3 3` not `1 2 3`. You can fix it like this:

        for i := range xs {
		x := xs[i]
		go func() {
			fmt.Println(x)
		}()
	}

Which seems like it ought to be the default behavior.