@ Egin -> funny u mentioned about that when i read something similar to it in Ghost In The Shell: Man-Machine Interface (MMI) manga (which is comic).
the character in the manga disconnected her hands (her body being fully cybernetic) & logged into the 'net. if she could 'sense' her hand then she knows that she is still online. this is to prevent her from being unable to disconnect or disengage from virtual reality environment.
& as for trying to wake up from dream, what i usually do is force myself to shake so much (prayers help too) that i wake up from sleep. first is to shake the head then the body. not easy to do as u may not know if u're shaking your real body or dream body. <img src="/ubbthreads/images/graemlins/think.gif" alt="" />