How to upgrade to ice-cream sandwish Can i upgrade my gingerbread android (v 2.3.6) to icecream sandwish android (v 4.0)
It depends on the device if you want the official install but with a lot of devices you will be able to install a custom ROM running ICS. 

To check for the official upgrade go to settings -> about phone (or something similar) -> phone update/update software (or something similar).

For a custom ROM have a look on XDA developers, I would give more information if I knew which device you were speaking of.