I was going through my file cabinet a couple days ago tossing old papers I no longer need. Among other things, I found a folder labeled "Warranty - Hardware" for computer hardware I've purchased. On some of them, the ink was so faded I could not longer read what the receipt was for.
I came up with an idea for keeping track of receipts. Instead of putting them in folders based on what the item is or when it was purchased, why not put them in folders based on when the warranty expires? So I'd have "Warranty - 2007", "Warranty - 2008" etc and "Warranty - Lifetime." At the end of 2007, I'd toss all the receipts I don't have a good reason to keep in the shredder or recycle bin. That would also be a good time to go through the "Warranty - Lifetime" folder and toss any receipts for items I no longer own.
This system only leaves one problem: how am I going to be able to quickly locate the receipts if I need them? Organized by warranty expiration date isn't exactly intuitive. I think a good way to handle this would be to keep a list of what I bought either in a notebook, spreadsheet, or any kind of program that can handle making lists. I'd track purchase date, purchase amount, warranty expiration date, what I bought, and of course where I bought it. This list could also serve as a inventory of what you own.
I've started implementing a solution in the program Journler (Mac only) - Windows users may want to check out the program EverNote. I just have a folder called "receipts" and dump all this info in there. If you have a good scanner, you may even consider just keeping PDF's of all your receipts.
Hopefully this is helpful to someone.