Peegar is an Arduinio-style electronics kit that you design programs for by dragging and dropping Scratch-style objects around in a browser; when you're done, the program is converted to a brief snatch of sound that you transmit through the board by plugging a standard audio cable into your device's headphone jack.
The idea is to give kids access to a hardware prototyping environment that does not require USB cables, online accounts or software downloads. It's an academic project from University of Tokyo, and I just met the creator at SXSW, who says he's contemplating Kickstarting a production run. The mechanism is very cool, and I can imagine that you could adapt it for existing Raspi/Arduino-environments just by making a system-on-a-chip shield that translates between audio to data over the board's USB port.
Peegar is a super-easy hardware development system. By creating a program intuitively on a web browser, hardware will instantly start moving. Unlike standard prototyping kits, there is no need to install any software, nor member registration for setting up your program. All you need is a normal web browser, therefore you can program visually on your smartphones and tablets. Peegar uses audio cable instead of USB cable to transfer the program to your hardware, which is another special feature to make development simple. Teachers can easily introduce how programming works to their students at school. Moreover, adults that hesitated to learn programming can start their new challenge. "Peegar" comes from the cute sound when sending the program.