[flashingpumpkin]

We've adopted a way that allows us to do basically this:

    mainWindow.menu "File", (err, file)->
        openMenu err, (err, menu)->
            getItem err, "Open", (err, item)->
                click err, item, (err)->
                    getChild err, getChildType("Window"), (err, dialog)->
                        if err? and err instanceof NoFileError
                            # do stuff
                        if err? and err instanceof InvalidClickError
                            # do other stuff
                        if err?
                            throw err
                        # do stuff with dialog if no err
                        

Each function takes as first argument an error and as last a callback. If there's an error, the function just passes the error up the callback stack until it gets dealed with.

    fun = (err, args..., callback)

You can't pull that off if your code is heavily object oriented though:

    mainWindow.menu "File", (err, file)->
        # If mainWindow.menu errors, file is undefined 
        # and the call to openMenu throws an error
        file.openMenu err, (err, menu)-> 
            # ...

Breaking your code/api up with modules instead into classes fixes that.