If you've got a filing cabinet--or desk--overflowing with documents, or if you want more thoughtful file management in general, a scanner can save you space, time, and ultimately money.
The basic process uses OCR (optical character recognition) software to digitize documents, typically turning them into searchable PDFs. That software is often bundled with the scanner; just look for a device with an automatic sheet-feeder for big jobs. Otherwise, you'll have to keep manually adding pages.
The scanning process can take a fair amount of work. But once complete, you'll be able to ditch hard copies of some files, and reclaim valuable storage space. (Just be sure to hang onto important originals, such as tax filings.) You'll also be able to search through files quickly, allowing faster retrieval than in physical form.
If you're overwhelmed by the time required for that initial digitization, some services can tackle that task for you. Shoeboxed specializes in scanning business cards and receipts to assist in your accounting, while others, including Pixily and Scantronix handle many document types.
Zack Stern is building a new business from San Francisco, where he frequently contributes to PC World.