One method is to dispense with PDF and just view the scanned pages online as images or OCR'd text or point the user to a directory with the scans for the document. He then only needs an image viewer using a lot less of his machines memory.
Large PDF's also cause problems in the viewing computer. I was reviewing someones 25mb PDF the other day and it peaked at 3.3 gig memory use, which on a 2.5gig memory box meant it went into swap and slowed to a crawl. The viewer used there was evince. I scan to jpg and only produce a PDF if nagged http://www.collection.archivist.info/archive/manuals/IS44_Tektronix_602_display_unit/ As I serve from home and the upload is on the slow side individual pages helps there too. And when in a good mood I finish off a document thus http://www.collection.archivist.info/searchv13.php?searchstr=lucas+tp1 where all pages are web viewable. Been too lazy to write a page to page link on the page view so far (need a round tuit). Dave Caroline