openDIAS (Document Imaging Archive System) provides document imaging with OCR. You can scan documents (with SANE) or import office documents, then assign them tags. It can store all your letters, bills, statements, etc. in a convenient, safe, and easily retrievable way.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.