The Apple Store. I went there to buy a cable and I paid with my AMEX card. They guy asked me if I wanted a paper receipt or e-mail. I said e-mail. He said thanks, bye. I walked off. It was only when I got out of the store I realised that their system had recognised my AMEX card because I use it to buy things from the Apple Store online, so they knew my e-mail address. Excellent.

I wish more places could hook up this way. I don’t generally want paper receipts at all.