Plus you have to realize that 50 % of 42 min is not that much. On little use I almost made it to two days before I was down to 20 % and plugged it in. My cell standby is usually around 20 %. So I wouldn't be to concerned with cell standby being 50 % of your battery after only 42 min. Plus you have to know that 90 % is somewhere between 90-99. I leave GPS turned off all the time after learning of that problem they found about the GPS, see the post Aminaked put the link for. Also if you have Wifi at home you will use less battery power being connected to that than your phone trying to search and keep 3G signal.