Hi Bryan,
you can use Mac OS X to compress your PDF file. Note however that you can do
this from Mac OS X 10.3 onwards only; since you're not stating which version
of Word and Mac OS you're using, this makes it of course kind of difficult
to help you.
There are two ways of reducing the file size of your PDF:
a) in your print dialogue, choose ColorSync, and apply the "reduce file
size" filter. This reduces the quality of your pictures quite a lot, so it's
not only a compression, and the final results might not satisfy you.
b) create your PDF file the way you usually would, and open it with
ColorSync Utility, located in your Utilities folder. Create a new filter,
name it any way you want. Under "Details", select "Images" from the dropdown
menu, and "Compression" from the next menu. You can now choose to define the
quality of your images, just play around with the slider and see what
results are best for you. Save the file, and, in case you want to repeat
this more often, also make sure that you save your new filter.
Michel