My printer can scan to a shared drive on my home LAN, saving files as PDFs. These are then uploaded Google Drive where everything else happens automatically (e.g. if you search for something, it will find it in scanned PDFs automatically).
Its super-useful especially since the mobile clients for drive is rock solid. I can be on the phone to someone and pull up basically any document I've had since the 90s in a couple of seconds, for free. Its kinda fun being on the phone to a call centre and being able to pull up data quicker than they can. Tax returns are an absolute doddle when everything is paperless.
The only thing that is missing for me from Google Drive is like a "Knowledge Graph" for my own documents - I can search by keyword or filename etc sure, but I'd like to get some "intelligence" next like we're used to with Google Now, but for my scanned docs, like "show me my bank statements with a payment to Amazon in the last 3 months" etc.