One of the things I enjoy most, with my camera, is playing with the shutter speed. A longer (or shorter) exposure time can create interesting effects, as for the school of fishes shown below (picture taken at Osaka aquarium a month ago).
Of course, this also works with us humans, especially in busy places such as Shibuya or Kyoto.
After all, aren't we just one large school of fishes, swimming through the highs and lows and the chaotic streams of life? (just kidding! ^^)