One of the neat features of second life is called particles. These are like free floating textures. So if you go into second life and see fire works or smoke or flames coming out of some object, most likely that is done with particles. One of my flickr contacts, Torley Linden, took pictures of a set of particle streams made by another Second Life resident Summer Seale. These show very nicely the artistic side of particles beyond using them for mundane effects such as fireworks or falling leaves.