Previously when I found some relevant and interesting Journal papers, I printed all of them, read them and highlighted with sighted pen. From time to time, I kept a great amount of printed journal papers and it costed me a lot of time and space to category and file them. Now with iPad, just click the pdf file button from the Journal sites with my library search, the pdf is then transferred to my iBook. All my relevant and interesting Journal papers are now in my iBook of iPad. It changes my reading habbit.