...or anywhere you're using a 'let' statement. I write a lot of OCaml, and I write a lot of multi-line anonymous functions that aren't stateful. I think it's less common to do this in Haskell, but that's more because it's Haskell than because there aren't any side effects.

Random other tidbit that doesn't deserve its own comment:

In Python, instance.method is the same as doing ClassName.method(instance). This can be helpful when using map/filter, because you get to do map(ClassName.method,lst) instead of map(lambda x: x.method,lst).