Why limit it to the rock...

How about the sword of the wizard's mind.

Where when you pick it up you lose control of your character for 30 seconds, gain control for 20 seconds and so forth. <img src="/ubbthreads/images/graemlins/biggrin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/ROFL.gif" alt="" />

I.e you could walk east,north cast spells/use skills(not harmful) but you get the idea.