iMac Core 2 Duo underclocking

Hi there, I would like to know if it is possible to underclock the C2d processor on my iMac (2.0ghz Intel Core 2 Duo, Late 2006 White Model). The reason being I only run one program at once (either Safari or iTunes).

Is this actually possible and if so, would it have any benefits in terms of reduced power consumption and heat? Your answers are appreciated thanks

It would have no benefits apart from the chip maybe lasting 25 years instead of 24, I would have thought.