Here is one company committed to Green alternative fuels and reducing carbon foot print. Google is no less a real life research lab. Plugin Electric cars are the fastest way to remove dependency on oil. They may eventually become energy hogs (if everyone will buy these), but for the moment, they are a viable solution. Advances in renewable energy may make electric even cheaper, easy to produce - until then, its only time for ideas.. like these..
Application cache (appcache) is a powerful feature in HTML5. However, it does come with baggage. Many (see links below) advocated ferociously against it due to tricky issues it comes with. For someone who is just testing waters, these issues may throw them off grid. Knowing them before hand helps reduce some unpredictable effects.