This is an extremely compact laser pointer which will play nice with both the iPhone and Android-powered handsets, where it will be accompanied by a presentation control app to make sure that your presentation will not suffer from any potential hiccups due to hardware.
The iPin can be clipped to your headphone cable whenever you are not using it. As for the amount of juice in which it draws, it will use the same amount as that of a regular pair of headphones without losing any of its effectiveness. In order to work through your presentations, you can use swipe motions to switch slides, or to utilize a remote mouse pointer. The $56 asking price might be a wee bit steep, but at least the iPin is more portable than most laser pointers.