Personally, I would like to see more performers rangling their own effects and practicing with them prior to recording. Mike Patton a fine example. He controls all his own effects, and live the sound guy just mics the his speaker and its done. The effects actual become an integral part of the performance and they are consistant in both live and recorded form.
In much the same way that guitar players use effects to alter the tonality of their instrument, so too can the vocalist. I think this takes considerable skill to master, but the result can be unique and effective (no pun, really).
Of course, this will not work for most performers, or anyone who simply wants their voice reproduced in a way that's flattering.