Something I’ve been doing to reduce the amount of stuff our family saves is replacing all hard copies of product manuals with digital copies and organizing them with the free Calibre e-Book Management software. So far I’ve been able to find a PDF version of all our manuals online and Calibre makes storage and retrieval a breeze.
This hack would work with any software able to store and index PDFs (including your computer's hard drive and built-in search function).
HOWEVER: this may be one of those rare times when one can be too organized. I can recall only a few occasions I ever needed to refer to a product manual (usually, for electronics, cameras, etc.). Surely, knowing they are online, I can look them up when I need them rather than downloading and storing them "just in case."
Another argument for paper (and something I mentioned during a past conversation on organizing product manuals): you can staple the receipt to the manual and file it away (or throw in a shoe box) in case you ever need to take advantage of many products' long quality guarantees…something usually forgotten in the mists of our overcrowded brains.
Thoughts? How do you manage product manuals?