The iPad fom the viewpoint as a consumer of information:
iTunes Podcasts, iTunesU , K12, Beyond Campus

The 'new' Library: ePubs, PDF's, stand alone publication Apps
Bookstore/collections: iBooks, Free Books app, Kindle, Inkling (purchase single chapters, discuss the future of textbooks), Overdrive
Periodicals: Zinio, standalone magazine apps
Standalone Book Apps: Al Gore's Our Choice

Discuss Scientific Mind: Skeptical Cynicism & Media Literacy & Research
(Rainforest Tree Octopus), Secondary Teachers: Google Scholar Searches

2) iPad as a tool to Amplify Understanding, Extend the Senses, Collect Qualitative and Quantitative Data: the App explosion!
See screenshots of Apps I may demonstrate depending on the audience, type of deployment.
Emphasis is on data collection and the unique embedded technologies that provided digital (Numerical) Data: gyroscopes, compass, geolocation, accelerometer, microphones and cameras. 

Discuss the role of simulation type apps vs. real hands on experiences. (my Masters Thesis was on this topic. 

3) iPad as a Communication Device
(a large part of what science teachers, science students and professional scientists do is communication)
Discuss visual literacy's role in classroom culture, understanding of phenomena, problem solving, record keeping and retention of concepts.
I often spend some time discussing learning theory, science vocabulary, mind mapping vs. concept mapping and brain theory. Haven't found a good inexpensive iOS concept mapping tool yet, so we do mind maps and may export then annotate in one of the freeform note taking apps. 

This is where some of the 'digital story telling' apps come into play. Spreadsheets, graphing, visual lab reports, audio reflections, field trip comics, video interviews, note taking apps, collaboration apps. 

FaceTime- virtual field trips, expert and scientist interviews, plan, execute and debrief (presentations) collaborative projects or experiments between classrooms, schools. 

Although historically most science textbooks have begun each year of K12 education with the 'Scientific Method', the vast majority of our students graduate high school never having designed an experiment (intentionally with an application of this so called 'scientific method'). In my perfect world of science education, students will have designed their own investigations each year (or at least several times during their K12 experience).