I have been getting worried signals about the economy in US. And it is not just me but grey panthers who have been through the hard times (e.g. oil crises). And here's a recent book about "The coming collapse of the dollar.." which predicts that the US currency system must come down sooner than later.
An amateur web-site that nicely summarizes the US economy in a nutshell.
It came as a surprise for me that the US Federal Reserve is a private corporation and not a central bank per se. The government does not own the bureau but a number of largest banks/bankers do! Sounds quite amazing. Check Wikipedia and you start to get the picture. And here's a script you can ask a series of questions directly from Fed or just read the answers...
Here are a few interesting approaches with alternative energy forms:
MiniC.A.T a car running with compressed air
Miniature jet engines for mobile devices.