EverNote
Keep notes and much more on a variety of synced devices, including tablets,
GoodReader
This application by Good.iWare Ltd. allows you to annotate PDF files.
itunes.apple.com/us/app/goodreader-for-ipad/id363448914?mt=8
Google Docs
This set of productivity tools is hosted in the cloud by Google.
iAnnotate
This app turns your tablet into a handy tool for reading, annotating, organizing and sending PDF files.
iCloud
Apple’s cloud-storage solution handles music and photos as well as documents.
Microsoft OneNote
This easy-to-use, powerful note-taking app is part of Microsoft Office. OneNote Mobile lets you create and view notes and lists whenever you need them.
itunes.apple.com/us/app/onenote/id410395246
