Over and underclocking it

[zakeen]

Hi I dont know much about this topic so I have a few questions.

Is overclocking it bad?

Is it possible to have like a switch mode? - Like have a real fast overclocked version and then and real underclocked version to save battery? Would this save battery if you underclocked it?

Thanks for you answers?

[Rudegar]

overclocking it can cause the device to take damage
overclocking it will eat more batt then a normal speed

otherwise read here
http://forum.xda-developers.com/viewtopic.php?t=10292