Piper will back your keys up to a flash drive if you wish. So I keep my keys on paper and on a handful of flash drives distributed geographically around the world. You can also use your own USB laser or inkjet printer.
You can do it either way. You can buy your own Raspberry Pi, which we sell preloaded with the Piper software here: http://cryptographi.com/products/raspberry-pi-w-piper-software-preinstalled
Or, you can just buy the Piper SD card which also comes preloaded with the Piper software (you'll need your own Raspberry Pi) here: http://cryptographi.com/products/piper-sd-card
Or, you can buy your own SD card and Raspberry Pi and flash it with our software image, which you can find here: http://piperwallet.com/sdimages/
In case anyone's wondering what the deal is with Cryptographi.com, it's the new company behind Piper. We've just launched the new web store for Piper on Cryptographi.com so that is where you can now place your orders for Piper.
Thanks everyone!