iOS owners have another way to view PDFs files on their devices now that Adobe has released its popular Reader app for iOS. Adobe Reader for iOS lets you open a PDF from any app that supports "Open in," including mobile Safari and iOS email. It'll let you open password-protected files and view additonal PDF content like annotations and drawing markups. It also supports bookmarks and thumbnails, both of which can be used for navigation.
The app is desinged to be a reader only and has a minimalistic interface. When you are within the program, you can search the document, copy text to the clipboard and print. The Adobe Reader app is available for free from the iOS App Store.