[sweeps]

I highly recommend saving receipts. There are many times we had to dig up a receipt to return or exchange something or get a price adjustment -- sometimes months after the fact. They can also be useful for finding tax deductions. Last year we put too much into our Flexible Healthcare Savings Acct and went through the receipts to find health-related purchases to maximize our refund.

I don't think there's a strong need to organize receipts other than by year. In my experience it doesn't take too long to go through and find what you're looking for (especially if they're roughly in chronological order).

Shred/recycle all your receipts that go back before the previous calendar year, they're pretty useless.