I'm asking what are the low-wattage consumption ETHO-able systems.

The Beagle series of boards backed by Texas Instruments, especially BeagleBone Black (www.beaglebone.org). It is the same price range as rPi, but it is true open source. You can load the design files and you can modify them to produce your own derivative boards to suit your needs. Most important, you can build these boards because you can buy the processors. You can build the exact copies of BeagleBone if you wish so, though it makes little sense because you can just buy these. Or, most importantly, you can build your modified versions. The biggest impediment of rPi is that it is available from only one place due to Broadcomm hold on the processor and the personal union between Broadcom and the rPi Foundation (both run by the same person). Broadcomm has killed the competing rPi clones by simply refusing to sell the CPUs to the independent developers. Even if Broadcomm changed this policy (which I have not heard of), you simply cannot trust the chip vendor with this track record. IMHO, investing any effort into rPi is a dead alley if you have any plans of "selling these boards to rural Africa". Simply put, you are at the mercy of a single source who has a track record of using dirty practices against the competition. This is contrary to the idea of open design. I am currently working on a BeagleBone which I selected precisely because I can buy the processor chips from Texas Instruments who has never refused to sell their chips to anyone. I am not impressed with performance, quad core or whatever. My only concern is whether I can build what I design, and then "sell to rural Africa". Therefore, the rPi is completely ruled out forever. Visit www.beaglebone.org and you will be impressed with the software projects that Beagle is running. You will quickly see that the Begle is *the* platform, rather than just a platform. There are many cheap boards around, but I found only one which: -- is cheap -- is open source -- can be redesigned or cloned -- you can actually build your redesigned versions -- has a backing by a large company -- has a very active user and developer community -- is running a wide variety of software, including several Linux versions For these reasons we are now investing effort into designing our own Beagle clone to suit our needs. The clone will be commercially available from our company when the work is done. Wojtek