This week saw a number of profiles of a new generation of activists. Some use the latest technology to promote the environment, some are resorting to radical measures to make their voices heard, and others are tuning back into the spirit of "countercultural questioning of values and priorities".

Julia Butterfly Hill and friends retrofitted a bus to run on vegetable oil and is traveling across the country on an educational tour:

Here's more details on how the bus was retrofit with energy-efficient, sustainable materials and technology: