For those few of us that don't have any device with a built-in capability of interpreting QR codes: http://zxing.org/w/decode?u=http%3A%2F%2Fwww.datagenetics.co...
One of the more creative ones I've seen recently is creating a really long-term data storage (Giga-Year) based on QR-Codes - http://vimeo.com/77028789