I've been through a lot of paperwork in the last few months. I've imported a car from the US, sold another car, adopted two cats, closed an investment account, and looked into getting a Line of Credit from the bank. I'll also be going through last year's invoices and expenses soon while preparing my taxes. Many of these things produce and/or require various documents. Here's a tip that has saved me several times already:
Whenever you get an official document like your car's registration or smog test results, or a Notice of Assessment from the tax people, take a picture of it with a digital camera and put it into your computer. If you've got decent photo management software, like iPhoto or Picasa, your document image is now stored with a timestamp and can be put into folders or tagged with keywords. That way it's always available simply by browsing or doing a quick search. You can also do this with cheques that you write and receive. That way you know what went out and came in and when.
No more will you have to sift through your actual filing cabinet to find some random piece of paper you got five years ago. No more will you get to the car place after several hours of traffic and waiting and discover that you forgot to bring the one key piece of paper. No more will you find yourself wondering what that $3750.27 deposit was last June and whether it was from invoice 517 or your tax refund.
If you keep your hand steady and use the macro mode on a decent digital camera (mine is a 5 megapixel Canon Elph), and adjust the contrast etc. in your software, you can get an image that's almost as good as a scan - without losing all the desk space that a scanner takes up. Most places that deal with paperwork get a lot of faxes, and a printout of a decent photograph is much higher quality (and frankly more difficult to forge) than a fax - also if your computer still has a modem in it (many laptops still do) you can fax directly from your image program, and the fax at the other end will be much sharper than a regular fax, since it didn't have to go through the cheap scanners used by most fax machines. Many places - even banks - also seem to have no trouble with an emailed PDF or image as a replacement for a fax.
It's taken me a while to get over the old paradigm of a camera only having 24 pictures in it, each costing quite a bit to turn into a piece of paper that's just going to take up space. Digital cameras can hold hundreds or thousands of pictures which are at once more ephemeral and more permanent than the paper ones I grew up with. I now do things like take a picture of my car at the long-term parking lot when I travel, so that I can find it again more easily when I get back - and then I just delete the image.
Of course if someone steals my laptop then I might be in trouble - except that 1) I make backups of my photo library pretty regularly so nothing would be lost, which is an improvement over single copies of paper documents, and 2) if I actually did lose my laptop, having someone find my Notice of Assessment would be the least of my worries!