Unlike the iPhone, the iPad just calls to be swiped sideways and scrolling up and down on it just doesn't really feel right. The iBook app is a great example of how convenient this gesture is. Unfortunately, it only reads eBooks in the ePub format.
Should that prevent you from reading your eBooks or documents saved as PDFs in it? Nope, as you can actually convert these into an iBook-friendly format. Simplehelp just posted a great guide on how to achieve this neat trick, so go check it out: