A London-based charity specializing in recycling computer technology for use throughout the developing world has calculated that it has saved over 150,000 computers from being disposed of improperly in landfields.

From the article:
Tony Roberts, charity founder, believes recycling is the greenest option under the European Union Waste Electrical and Electronic Equipment (WEEE) directive, introduced to boost reuse, recycling and recovery of electrical goods.
With nearly 80% of energy used by a computer occuring during its actual manufacturing, efforts to keep current computers operating as long as possible has proven to have a positive impact on the environment and sustainability efforts.