Ever since I upgraded to CS2 my PDF files are much larger than they have been in the past. What's up?
Check the PDF settings.
Choose Edit > Adobe PDF Presets...
The Adobe PDF Presets dialog box appears.
Select Smallest File Size.
The Preset description will help you to determine if this PDF settings suit your needs.
If not you can always click the New button and create and save your own settings.
The next time you save your Photoshop files as PDFs, they'll be the perfect size.