Quick facts on Bio-Diesel:
An acre of soy (the main source of bio-diesel today) can yield 50 gallons of fuel-oil per year.
An acre of an algae-lagoon can create up to 20,000 gallons of fuel-oil per year.
Certain strains of algae are more than 50% oil by volume, and algae doubles in volume every 24 hours. EVERY water treatment plant and farm could be diverting "waste water/sludge" into an algae -lagoon. The waste feeds the algae, along with sunlight and the right temperature range. Algae then fuels the operation and creates a valuable local energy-source.

Along with many companies investing to develop the technology needed for this: http://earth2tech.com/2008/03/27/15-algae-startups-bringing-pond-scum-to...

Middlebury College is also paving the way to an Algae-economy, as well as technology that will "scrub" C02 emissions from power-plants and use the C02 as an input to grow algae.

http://www.middlebury.edu/about/pubaff/sstory/fellowstudents/news/2007/p...

According to a study by experts in bio-fuels a the University of New Hampshire, algae could easily fuel our ENTIRE US ELECTRICITY AND TRANSPORTATION NEEDS, with less than 10% of the Sonora Desert being used for algae-lagoons (15,000 square miles) and an investment of just $169 Billion. Read the full study by Michael Briggs here: http://changethis.com/9.biodiesel