try plugging into the specular channel some material you can create in the material editor with marble or spots or some combination of these, and mess with the stregnth of the specular settings. or if you want i'm pretty sure the hyperreal products by faceoff will apply something automatically. if you are gonna animate it, you should take a v3 texture to your photo editor (resaving it so you don't damage the original of course),blank the texture, like probably black, but with the edges still defined, and create streams in separate layers, pretty easy in photoshop, and move these layers down the v3 template snapping a pic of each step. then you could composite the frames, load as an avi into the specular settings, and voila, running water down the body.