Dropbox has added two-factor authentication in a pre-release version of its software. The two-factor method requires a password plus a token delivered via another means, such as SMS or a special code-generation iOS app. At Macworld, Dan Moren explains how to use the new option, which reduces the chance of third-party break-ins, as a password alone no longer provides access. But note that AgileBits is recommending that 1Password users who rely on Dropbox for syncing passwords hold off for now. follow link
Two Shortcuts for App Exposé
If you want to see all the windows for a particular app via App Exposé, there are two hidden shortcuts. For either, start by pressing Command-Tab to bring up the app switcher. Then, while still holding down the Command key, press either the 1 key or the up arrow. That puts you into App Expose mode, with all of an app's windows showing, and recent documents in a row across the bottom of the screen. Let up on the Command key, and then you can press Tab to cycle through all the running apps.
Dropbox Two-Factor Login Explained by Macworld