Rotate 90 Script/Hotkey

 From:  Stien (UNCLESTAN)
8224.1 
Hey yall,
Simple question here. Is there a command that I can bind to a hotkey to rotate the selected object by 90 degrees?

eg.
x= Rotate 90, x-axis
shift+x = Rotate 90, y-axis
alt+x = Rotate 90, z-axis

I suppose the pivot would be the bounding box center.. just looking to skip clicking the GUI arrows when rotating a bunch of things.

Thanks