I have noticed that whenever I open iPhoto, the estimated battery time left on my MacBook Pro 13" is reduced by more than half! All I have to do is open iPhoto and within seconds the time reduces considerably. The moment I quit iPhoto, the estimated time jumps right up again. I have found that if I place my ear close to where the hard drive is, I can hear it become very active while iPhoto is open. This must be why the battery time goes down. Other programs don't cause this same level of hard drive activity. Is the increased hard drive activity normal in iPhoto? Does anyone else notice this? Edit: Just realised what's going on! iPhoto was scanning the entire library for faces!