This Digital Mix Tape is awesome. It's just a small USB drive wrapped in a cassette tape packaging. The idea is that you put together a MP3 mix for someone just like us really old people used to do on cassette tapes. You could even make your own from old cassettes and all those small USB drives you end up with.
It's also a good piece of marketing. I could easily see someone using this idea for a mailer. (Via RetroThing)