Shoeboxed is a service that manages your receipts. You scan receipts and e-mail them to Shoeboxed, or just use their iPhone app to scan receipts, or you can even mail them paper receipts if you want to, and they have real people review the receipts and organize them into categories. If you use the service to manage all of your receipts, then by the end of the year you have all of your expenses organized and available in multiple formats including Excel, PDF, etc.
I have had the Shoeboxed app on my iPhone for a while now and had intended to try it out, and then I read that my friend, New Orleans attorney Ernie Svenson, has incorporated this app into his daily life. Thus, instead of me doing a review after a week or two of usage, let me refer you to Ernie's excellent and comprehensive post. I am already loving that with the Chase app I can just scan a check to deposit it without having to visit a bank. Scanning receipts sounds just as easy considering that your iPhone is always with you when you get those receipts.
If you are looking to go paperless with your receipts and like the idea of having a service do the hard work for you, check out Ernie Svenson's post on Shoeboxed.