Someday a great standard/accessory slim battery (5000 mAH) will be developed to supply smart-phones, right now the BATTERY seems to be their achilles heel.
Its Ridiculous to not use your smart-phone in order to get good battery life, and makes no sense to turn off features which makes a smart-phone... well SMART.
Everyone has a plan/strategy to get better battery life, turn off bluetooth, lower brightness, don't use GPS, Turn off Apps, leave Apps alone, turn off data, don't use LIVE WALLPAPERS, stay off internet, don't use camera, lower this and shut off that, here's a tip to great battery life... keep your phone turned off.
Back to reality... USE YOUR PHONE, ENJOY IT.
here's a secret i learned from a cell phone developer... not many people know this... carry two extra slim batteries and switch them when the phone battery runs low. Pass it on.