Design 21: Social Design Network

I am a young designer in a post-undergraduate transitional phase (to put it nicely) and am looking for some advice on the next step in my career. I am interested in pursuing some kind of industrial design, environmental design, mechanical engineering, or some combination of the three. I am going to take some courses in these concentrations over the next few years to feel them out a bit before making any big moves. My big question is: what job to pursue in the mean time? Any ideas on a good starting point/base for experience? I'm considering continuing with a graphic design job, but I'm wondering whether there is some other field or job that might give me better broad experience and let me experiment in the areas of industrial and environmental design. Anything would be appreciated! Thank you, Sam