
I still keep all of my receipts in hanging file folders, grouped by year. Occasionally I do have the need to dig through and find an old receipt, usually because I'm trying to get a failed product replaced under its warranty.
Keeping the receipts also lets you add up the sales tax and use that instead of the standard deduction on your income tax. (And of course if you do that, those receipts become a part of your federal income tax filing and you need to keep them for 3 years in case you get audited.)