What I usually do is printing the file through Adobe distiller. So, I open a graphic or large pdf file in photoshop or illustrator and when I normally save it as a PDF it gives me a, let's say 10 meg file, ok? Well, that's not what I want so I go to print and select Adobe distiller. Most of the times a file that size will be downsized to a couple of hundred kb. Distiller is part of adobe acrobat, the writer that is, not the reader. It's also possible to open the pdf in acrobat and use the reduce filesize option. Good luck and if it's not working, drop mail me. Attach one file to try it first. Otherwise my mailbox gets overloaded.
Manfred