This could be interesting.

Late Wednesday, TapMode president, Jeff McMorris, launched, Battery Gauge, a new iPhone/iPod Touch app that learns a user’s patterns and intuitively keeps track of projected battery usage required to carry out tasks.

Per MacMegasite, McMorris came up with the idea for Battery Gauge in order to solve a problem in his own life. “I needed an app that would give me an idea of the actual time I had remaining on my battery, that would look at how I used my phone and then base its estimate on that usage pattern.”

The application reportedly takes into account all of a user’s normal iPhone or iPod Touch activities. Each task uses a different amount of charge which Battery Gauge analyzes.

Battery Gauge 1.0 requires iPhone OS 3.0 or later to install and run and retails for US$0.99 in the App Store.