[mindslight]

> as far as I can tell they're only used for "threading" state through a series of functions

That is why people bump up against them when learning Haskell, but monads run much deeper in functional programming.. Even "pure" functions in Haskell are monadic with respect to the non-terminating "bottom".

I said it elsewhere in this topic, but check out Moggi's "Notions of computation and monads".