Google Drive is a web-based file synchronization service launched by Google on 24-April-2012. It replaces Google Docs and provides 5 GB of free storage, with the option to rent up to 1 TB of storage.
In addition, there are Mac, Windows, Android, and iOS (iPhone/iPad) clients that allow for automatic synchronization to/from local storage (similar to Dropbox).
See http://www.google.com/drive for the official page. You may need to log in first if you already have a Google account.