ORPALISPDFReducer enables you to reduce the file size of bulky PDF files by compressing and downscaling images and discarding unused objects. The resulting files can often be less that half the size of the original (sometimes even smaller) without noticeable quality differences.
The program can batch process multiple files in a single operation, or you can switch to drag-n-drop mode to quickly process individual files from different locations.
The defaults settings work very well and reduced file sizes by up to 90% during our tests - the results may vary depending on the content of the PDF file. You can further tweak the settings by adjusting image compression and other aspects of the size reduction process.