The best I can suggest after the social networks is to make sure that the Wi-Fi Sleep Policy is set to Never. I generally still get a higher percentage of Android OS, sometimes as much as 30%, but it is usually when there aren't other things eating up more battery, like the display. Something I have noticed about it is that if I select Android OS in battery info, where it shows the percent, it also tells CPU use time, which seems to run about 3 minutes for every hour of uptime. This is much higher than I have seen on other phones I have used, but I can still normally get a whole day out of it with light to moderate use.