I also noticed that SmartPlanet touched on this three years ago, before my time on the blog. I gather there haven't been great technological or engineering strides, as I haven't noticed any glaring headlines anywhere - just the occasional golly-gee article.
To elaborate a bit more on what Archer and Caldiera explained, engineers have proposed two different methods for capturing and converting the jet stream's energy.
One, backed by Italian company Kite Gen, would use air foils to grab energy at altitude and transfer it mechanically via cable to earthly turbines - as pictured at the top of this story, and as visually displayed in this YouTube video, backed by New Age electrobeat music (perhaps a sure sign that we're still a fair age away from jet stream-lit cities):
The other would mount turbines on kites tethered to an electricity grid on land (or sea) by kevlar-insulated, aluminum conductors, as in this YouTube video from Sky Windpower, a San Diego company:
The practicalities of these systems strike me as challenging, to say the least. For grandiose schemes, I think I might prefer the vision of generating electricity via satellite-mounted photovolatiacs and beaming it back to earth.
Either way, you gotta dream.
For now, I'm organizing troops to lasso the jet stream and haul it back up north where it belongs. Otherwise I wasted about $11 on the sunscreen I bought a few months ago.