Instapaper
I have been using the app Instapaper ($4.99) on the iPad for a few days and have really enjoyed it. Simple concepts like this make the iPad a great device for learning. Instapaper is a free website with $5 app that allows you to download online content for later reading. In the past I have done this by emailing myself links, using Evernote or starring things in Google Reader. Now I just use the bookmarklet and the content is saved to my Instapaper account and synced to the iPad the next time the app is opened. When I find a few minutes of downtime I do not have to search for the content I had glanced at earlier, it is already synced to Instapaper. I can see this being a great tool for teachers and students who want to refer back to web content for tests and quizzes or homework reading.