Corbis have just released a set of make-your-self, print out and assemble pinhole cameras. I'm considering using one for the second book, as I've got a pile of film around the house I'm probably not likely to use for anything else.
A second option is evolving around the idea of losing focus and exploring making images that are not perfectly, or even at all, in focus. I keep flirting with this idea but haven't really made much in roads. Perhaps committing to it for a month would help me explore a bit deeper.
I do feel burned out on shooting portraits, for now. I think I might find an area of shooting that is a bit more restful and contemplative. It has been fun shooting all these people but the interaction is wearing me out. Building up to asking people, dealing with occasional rejection, being sociable. Time to shift gears and find a slower subject to help me recharge.