Finally, my Raspberry Pi arrived last week. I had placed my order around April so this was a long wait. But it was worth it!
In case you haven't heard about it, the Raspberry Pi is a $35 bare-board computer intended for school children to learn the basics of computers and programming. It is promoted by a non-profit organization (the Raspberry Pi Foundation) and fills the void left by the demise of the small personal computers of the 80s (such as the ZX Spectrum, the BBC Micro or the C64) on which many of today's scientists and engineers (including myself) first learnt to program.
Of course time has moved on, and the Pi can now be made so cheaply by using high integration components from the mobile phone industry: a system-on-a-chip comprising a GPU, CPU and 256MB of RAM; an SD card slot for persistent storage, an ethernet port, HDMI/composite for display and USB for input devices (or more storage).
The principle difference between the Pi and a smartphone (regardless of price) is that, unlike the later, the Pi is a general purpose programmable computer running a generic GNU/Linux OS. Yes, you can buy or download an SDK for an IPhone/Android but that is a much higher entry barrier. And the higher cost and utility of a smartphone/PC discourages anyone from tinkering with it.
Because it runs an open-source OS, the Pi is remarkably agnostic regarding programming languages and environments. In a couple a days I have successfully tried C, Python, Haskell, O'Caml and Prolog.
I teach programming to first-year CS students and intend to use my Pi to show how abstraction allows running the same high-level program developed in class on both the lab's x86 PCs and the ARM-based Pi: different CPUs, different memory size and storage devices, different flavors of Linux; but by focusing on a proper level of abstraction we can re-use the same source code on vastly different devices. We already tell them such things, but the Pi makes it easy to actually show them. And, as I get older, I realize that the persuasive power hands-on experiment is often underestimated in formal education.