June 04, 2012, 3:28 PM — Dropbox is the most widely used and simplest file-synchronization system worldwide not attached to a major technology company. Every machine on which you install Dropbox and use the same account has all the contents synchronized among them by default. Make a change on one machine in the Dropbox folder—remove a file, add one, reorganize items into folders, or save changes—and that change is instantly propagated to every other synced machine. That's the point of such services, and Dropbox consistently accomplishes this in a nearly invisible manner.
Install the software, and an anointed folder is the hub of Dropbox activity. The software offers support for desktop folder sync in Mac OS X, Windows, Linux, and allows mobile access for viewing and for uploading files, images, and video under Android, BlackBerry, and iOS platforms.
However, by keeping it minimal and avoiding a full-fledged client—it's just a menu with a few options—Dropbox requires heavy use of its Web interface for even basic tasks. That's a mild complaint, because the Web site works quite well, including allowing drag-and-drop copying from the Finder into the browser and dragging to organize items into folders. Still, better desktop integration would remove the remaining friction.
Sharing and collaboration
Beyond syncing across your computers and creating backup copies of your own files, Dropbox has several features that take storage and sync further. These include collaborative sharing with others, read-only sharing, accessing older versions of files, restoring deleted files, and uploading images from attached cameras and phones. A mobile app allows limited tools away from a desktop.
The collaborative sharing feature is one that brought me to Dropbox and keeps me there. Any folder may be shared with any other user (if they don't have an account, they can sign up at no cost and store at least 2GB). A shared folder is synced among all users who join it, until they remove themselves or the owner kicks them out. The contents of a shared folder count towards an account's quota. What's missing is the option to set read-only folders, something that could be tricky on the desktop (as it would involve setting file locks on particular users' files), but would aid in sharing material.