Will cars someday run on cardboard? How about sawdust? Weyerhaeuser and Chevron have formed a joint venture to convert cellulose and lignin -- two basic compounds found in plants -- into biofuels. Much early biofuel research has focused on converting starchy food plants -- like corn and sugar -- into ethanol. That's sparked criticism from some quarters, particularly opponents who think it's crazy to use our food to power our vehicles. It's also caused a run-up in demand for corn that in turn has caused huge price spikes in that and other grains.

Cellulose, on the other hand, is one of the most common organic materials on the planet, now commonly used for cardboard. However, certain types of bacteria are known to convert particular kinds of cellulose into ethanol. And the No. 1 source of industrial cellulose worldwide just happens to be -- that's right, wood chips. (Although some say that dead leaves, bark and twigs will work, and research is also being focused on certain varieties of grass.)

That's good news for Weyerhaeuser and other Northwest timber companies. The problem is that it's harder to convert cellulose to ethanol than it is to convert starches. But if researchers succeed, timber companies could be sitting atop a renewable green energy source.