gistfile1.py

    @property
    def centroid(self):
        lat_sum = 0
        lon_sum = 0
        point_count = 0

        for point in self.locations_points:
            lat_sum += point[0]
            lon_sum += point[1]
            point_count += 1

        return (float(lat_sum) / point_count, float(lon_sum) / point_count)

@property
def centroid(self):
    count = len(self.locations_points)
    total = reduce(lambda x,y: [x[0] + y[0], x[1] + y[1]], self.locations_points)
    return map(lambda x: x/count, total)

Not sure if it'll faster :D