There are a few free software programs that will read EXIF meta information out of a JPEG file. I looked at many of them in 2002 and found four that were of use to makethumbs: metacam, jhead, libexif, exif-tools project.
I think metacam is the best of the four, but handling EXIF tags for many different cameras is tricky so having more ways of getting information out of the photos is always handy. jhead is also quite good, and by virtue of being very small, is easy to build. Some pre-built binaries are also on the jhead home page. libexif's exif is quite nice if the text is reformatted a bit to be readable. dump-exif is the least good of the four; it is capable of reading the EXIF data but its presentation of that data is not so great. I'd recommend installing at least metacam, and also jhead on your system if you can -- makethumbs will switch between them until it finds something that works.