Everytime I goto the Apple Store in San Francisco, I am amazed at how quickly you can check out without a receipt, the receipt actually can be sent to my e-mail box, which I can confirm in real-time using my Blackberry GMail app.
Apart from the Apple Store, I don’t see that many other retailers using paperless receipts, perhaps it’s ahead of its time.
For those of you who want to tinker with such a system that will keep your receipts in a web server so your customers can retrieve it at their convenience, you can check out this cool hack that shows you how to make a digital paperless receipt system, with circuit diagram and code.
The basic idea is when making a purchase with a credit or ATM card, the transaction information is automatically packaged and sent to a webserver where it can be logged in a database. A web interface would then allow consumers to log into their accounts and view their transactions online all in one place.