Almost every Raspberri Pi owner uses it without a monitor/keyboard attached to it... One simple option is controlling the (mini)computer by ssh or directly by an iphone (thanks to xbmc + airplay, GREAT invention!). Anyway, after listening hour of justin bieber music you could think... "and now, how the hell I can turn this off?" after some moments of hard-thinking you end up with the simplest solution: unplug the power, no matter if the (poor) system tells you every time "the system was not shut down properly".
Next move: use google to search for "raspberry power off button". One of the most interesting site you could find is: http://www.3cc.org/blog/2013/01/raspberry-pi-shutdown-switch-safely-turning-off-the-pi/. Perfect! i will use the code reported there to turn off my very special media player! let me see the code...