Yesterday I had the idea during a bachelor party in which almost everyone had the same problem after 4-5 hours of intensive smartphone use; (almost) no battery.
Since i attended some events lately where I wanted to tweet, post pictures to my instagram or just check-in, I now pay attention to put myself in airplane mode and only put on data when I want it. The problem yesterday is that the airplane mode makes yourself pretty unreachable…
So the idea is a smartphone life hack: Create a default profile in which you can switch, just as easy as to and from airplane mode, but have text and voice active.
The main advantage is that you could be reached at all times. Another advantage is that you are more focussed on enjoying the event and handling your ‘online sharing urge’ stuff in a time-boxed way (I, for instance, did open my data connection every hour so I was not totally offline and did respond to most of the comments)