On the market! (although personally I think live wallpapers suck, mosly suck battery. I really only use them when I am showing my phone off to someone haha)
Yeah, I don't like the extra juice they draw although some are much worse than others.
A static image will always be the best for energy consumption. Apparently, a red background uses the least amount of battery power...which somehow makes sense intuitively as it is closest to infrared