Before shifting to LCD projectors and monitors, we used to transfer text material to 35mm transparencies using a POLAROID CI-5000S and PowerPoint. I haven't done that in over 8 years however. Prior to that, we used a Diazo Blue method.
Anyway with digital photos, you could insert them in to PowerPoint and transfer them with Polaroid CI-5000S or similar piece of equipment. You will then take your slide film to the lab to be developed and mounted.
Why not use PowerPoint for your Portfolio and an LCD projector?
Edit: I failed to mention that these devices like the CI-5000S have a 35mm camera body attached.