Just took this. I searched google images to try to compare it to a real black widow but I've heard that there are imitators with the red spot. Note the black/brown striped legs. I know that there are different variants of the BW but it doesn't look like any of the others I saw either.
Image 2:
Just been looking at NZ version of the black widow, seems the hourglass-shaped mark underneath make it for real.
This is indeed a Latrodectus spp. (widow spider). 'Black widow' spiders do not always have a bright and distinct 'hourglass' (see http://www.pbase.com/tmurray74/image/46541658). and some North American 'black widows' also have dorsal markings (see http://www.pbase.com/tmurray74/image/58704945
