Today is Earth Day and you can find out what's going on in your area by starting with the Earth Day Network. In the spirit of Earth Day, here's the next post in my ongoing Green series.

A number of interesting news items have hit the wires since my last green post. The University of Edinburgh has built what it claims to be the first green supercomputer. Fortune published its list of ten green giants, including Honda (the most fuel-efficient auto company in the U.S.), Continental Airlines (for collaborating with Boeing to engineer more fuel-efficient aircraft), Suncor (for measuring the environmental impact of each project), Tesco (for promoting green thinking to its customer and calculating "carbon costs" for each item), Alcan (for investing in clean manufacturing), PG&E (for investing in renewable energy), S.C. Johnson (for continued elimination of pollutants from its products), Goldman Sachs (for its bold climate-change policy in investing), Swiss Re (for developing financial tools to deal with climate change risks), and Hewlett-Packard (for its eco-sensitivity). And the Gaia Napa Valley Hotel and Spa Resort has gone green.

The green movement is still going strong. The Supreme Court has ruled that the EPA can regulate greenhouse gasses, Ontario is considering joining the U.S. greenhouse gas initiative, and Schwarzenegger is pumping up the green movement in. It's also going strong in the real estate market - but in a more literal way. According to a recent CNNMoney.com article, the number of buildings with green roofs grew 25% last year.

On the technology side, a start-up by the name of Ecotality plans to produce a prototype of an apparatus called the Hydratus that produces hydrogen fuel, as it's needed by a car's fuel cell, from a reaction between magnesium and water.

Finally, congratulations to Oakland, the cleanest city in the US according to SustainLane's government site. After all, It's Not Easy Going Green which, in the case of Las Vegas, means not going green at all!