Australia's new triangular 5$ coin. (l.yimg.com)

Source: http://my.reddit.com/r/pics/comments/1dz6s2/australias_new_5...

the comments in the source are the really interesting thing, actually.

FWIW, here are images of other triangular coins: http://www.dig4coins.com/articles/other-coins/triangular-coi...