In 1923, J.B.S. Haldane wrote "Almost all our present sources of light are hot bodies, 95% of whose radiation is invisible. To light a lamp as a source of light is about as wasteful of energy as to burn down one's house to roast one's pork."
Future generations will look at almost everything we have done and wonder what we were thinking.
Oh sure, but the RPi draws about 2W idle, less than 5W if it is really working overtime. Plus it's fanless and silent. It makes a nice little headless server for lots of things. And even used, cheap laptops aren't often under $50...
Well, given that they will by definition have mastered travel on scale which we have a hard time conceptualizing, I think it's not unreasonable to imagine that they won't be quite the savages we are. It's taken us the last 100,000 years to cut back on infanticide, ethnic cleansing, etc., so I'm fairly confident that by the *we* are the ones paying a visit to an exoplanet with a view, we'll be more benign, ourselves.
It's the same hardware, I think, but there's also the TonidoPlug, which costs $99 too, and comes with Jaunty preinstalled, along with some snazzy-looking apps (the roll-your-own OpenID seems groovy).