In almost all applications where you have to scroll down to find, read, or interact with information towards the bottom of the page, you usually get there by flicking up the view. The exception is in applications like “Contacts” where you can touch an index to scroll quickly to the beginning of any letter section.
When you are down there and want to come to the top, you can do that by simply touching on the “Status Bar”. The application will scroll to the top of the view. This is especially useful in Safari when you want to go to a new URL or perform a new Google search.
I also use it in the Contacts app to scroll to A, in the Settings app, and in many of my glossaries. Note that although it does not work in a few apps, you can reliably use this trick in a majority of the apps that let you scroll. These apps are not necessarily text-based either. You can scroll up in the Photos app as well. This trick works on your iPad as well.