Some of the biggest names in technology, including Google and Yahoo, have been talking up their green efforts for Earth Day 2008.

Google observed the environment awareness day by highlighting the green benefits of its products.

The company announced an expansion of the Google Transit trip-planning service, and a new Energy Saver Gadget for Google Desktop which allows users to manage power settings on their computers.

The Google.org philanthropic group also took time to tout the virtues of eco-friendly businesses.

"As we transition from a pollution-emitting economy to a green-clean economy, the task will be monumental. Millions of jobs can be created and a new economy can be born," wrote Google.org associate Shannon Oliver.

"Simply put, green jobs are jobs that are good for the environment, good for our planet and pay a living wage."

Yahoo, meanwhile, took time to team up with local recycling groups in a campaign known as Free Is Good.

The aim of the project is to donate unwanted items and materials, such as timber or old appliances, to groups which will then give them out to others, rather than break down waste materials for recycling.

"We have seen a grassroots surge in consumers looking for information about reuse, so we are using our network to help move consumers from awareness to action," said Yahoo co-founder David Filo.