Hot lead to cigarette lighter

I want to run a hot lead to the cigarette lighter so that I can leave my cell phone plugged in and turned on when the vehicle is turned off. Presently the power to the outlet goes off with the ignition.

Is there any reason I would not want to tie into the hot lead with a fused lead that does not turn off with the engine?

Thanks!
please email scottcurfman@yahoo.com

Look here
http://www.yotatech.com/showthread.php?t=35825&page=2