Instapaper - read internet articles offline (must sync while online, obviously) best $5 ever
http://itunes.apple.com/us/app/insta...288545208?mt=8
Dropbox - syncs with a folder on your computer $0
http://itunes.apple.com/us/app/dropbox/id327630330?mt=8
Goodreader - more of a great iPad app, but nice functionality for storing and marking up pdfs like those lido charts and flight pubs (e.g., searchable FOM in your pocket) $5 (dang, used to be 99¢ for iPhone and iPad) Anybody using something similar?