Thanks Aruna, that was most helpfull, I wonder if there's a way to do this with individual workflows though. I will keep on looking as I don't want to take down all workflows while I perform updates.
While I'm here, in a similar vein, does anyone know the best way of termporarily preventing people from submitting to a library while I make changes? I've been removing everyone's access to the gallery manually but this has been unsuccessful.
Thanks again Aruna though, this was most helpfull