Capetonian,
Bit messy that route.
For people who don't have the full Acrobat, next best thing is "PDF Shrink" from Apago (apagoinc.com). Only 35USD, so won't break the bank, and very handy tool to have knocking about.
However as hinted above, if you're not preparing the PDF for a litho press, you should always make an effort to reduce the size of the graphics you're putting into a PDF in the first place.