According to Apple's documentation, "The UIPasteboard class enables an application to share data within the application or with another application using system-wide or application-specific pasteboards." http://developer.apple.com/library/ios/#DOCUMENTATION/UIKit/...
For a couple examples: OpenUDID and SecureUDID use UIPasteboard.
For a couple examples: OpenUDID and SecureUDID use UIPasteboard.