Tipster Mike Kurent needs PDF files to be smaller, for many reasons. Here's a trick he uses to shrink them down.

"Our company needs to maintain an electronic copy of stamped/approved drawings. After scanning the drawing(s) and saving to PDF, I open the saved file in a viewer and print it to a PDF using a print-to-PDF application such as CutePDF. The newly generated PDF is usually about 50% smaller than the original."
 
Notes from Cadalyst Tip Patrol: Archiving drawings is very important; if you aren't doing this already, you should consider it. Signed and sealed drawings are not easily archived digitally — they must be scanned. Depending on your scanner's features, the file created may be very large. Check the settings on the scanner; it's possible the resolution can be reduced.

A scanned image often tends to be larger in size than it needs to be. One reason is because it is storing image information about the blank spaces on your drawing (the scanner sees that as data too, even if it is nothing more than white paper). Sometimes the white space is interpreted as grey in color. Printing in CutePDF or using the file reduction tools built into Adobe Acrobat Writer help to fix this. Storage space is limited, so use it wisely.