I guess skate and bike photography could benefit from a fisheye, but I see it more as a rarely used novelty rather than a really useful tool. Look at the Nikon/Tokina 12-24mm or even the Sigma 10-20mm before dumping all that cash into a fisheye. You may like the effect at first but I imagine it could get old fast. Plus most good skate photographers just stick with the wider end of the spectrum rather than using a fisheye. It gives it enough distortion to give the tricks a bigger feel while keeping the shot relatively realistic looking.