I think that most of us will admit that we have used things that were never meant to be a hammer to driving small nails. I know the last time we moved years back I couldn't find my hammer for anything and some pictures had to be hung on the way right then according to the wife. I ended up washing nails into the wall with a dress shoe heel and then resorted to using my adjustable wrench. Whacking too many nails with an adjustable wrench will eventually break your tool.
A company called Gedore has a new wrench that is specifically designed to be used as a light-duty hammer. The wrench is called the Gedore Adjustable Hammerable Open End Wrench and will sell for $40. The wrench can be pre-ordered right now with shipments set to kick off June 27. The part for driving nails appears to be the flat section on the back of the wrench.
It has a Swedish pattern adjuster wheel, an adjustment scale, and comfort grip. It is designed to be easy to grip even with greasy hands. It doesn't say specifically how large a nut or bolt the thing will accommodate, but it looks like it would work with hardware up to an inch or so. The adjustment mechanism is designed to be protected from the blows of hammering a nail.