I'm not sure if this is practical, but I think it ought to be. It would make a nice product if it is, and as it's beyond my abilities, I offer the idea for free. (If you turn the idea into a RMP item and make a lot of money, I wouldn't say no to a free copy!). The product would consist of a .psd file with several layers. The layers would contain patterns of water droplets (sparse to dense) constructed in such a way that applying the layer using the right blending mode to an existing skin texture file would make the skin look wet (or very wet). There are several wet skin textures in the marketplace, but I don't see why the wetness couldn't be handled in a completely generic way, so that any skin could be wetted. A similar thing would be to have a .psd file containing sandy patches, which could be applied to any texture to make it look as if someone had been sitting or lying on the beach.