An AskMetafilter user wonders how long to keep receipts:

I have been keeping all of my receipts for some time now. Every day, I enter them into my money tracking system (presently just a text file where I capture date, payee and amount). Then I file the receipts away in folders by month. My question: does it do me any good to save the receipts, or is having the data good enough? [...] I've never had to bring out individual receipts for tax purposes before, but my understanding is that if I got audited, having all my receipts would be very helpful. Is that true?

Bankrate has an excellent table summarizing how long to keep financial records. To summarize: