[Haskell-cafe] newbie "concatenating" monad question

Hi I'm new here and this is my first mail to the list, so be gentle :) I have some functions that build big strings by calling other functions and appending the result, like buildStuff = func1 ++ func2 ++ func3 ++ func4 My idea is to have a monad with a concatenating >>, so that I can: bulidStuff = do func1 func2 func3 func4 I am thinking about using the writer monad, but I would still have to use "tell". The list monad is not an option either, as it does not concatenate. Is there a proper way of doing something like this (efficiently) ? Leandro Penz