Jumping spiders are among my very favorite animals.   They look (and behave) like they're full of personality -- highly visual and alert, active, and seemingly unafraid.   They're aggressive predators that act like big cats: stalking prey and attacking in a leap or a rush, then biting and wrestling it into submission (sometimes they go for insects much bigger than themselves).   The first three images (top and below, left) are of an adult animal that is perhaps 12-15 mm long.  The last two images are of baby spiders newly emerged from their egg sac.   These are tiny (maybe 2-3 mm leg span at most), active, and extremely challenging to photograph (depth of field is almost nonexistent at 4X-5X magnification, and attempting to increase it by stopping down the lens will soften the images from diffraction effects).
       These images were photographed with a highly specialized macro lens and ringlight (which accounts for the odd reflections in the adult's eyes).   The adult spider came from Arizona (although I took the pictures in a colleague's lab at the University of California, Riverside).
            Images of other jumping spiders are here, here, here, here, here, here, here, and here.