SkyDrive, known as Windows Live Folders

SkyDrive (also called Microsoft SkyDrive or Windows Live SkyDrive) is a free-of-charge file hosting service that allows users to upload files to a cloud storage and then access them from a Web browser. It is part of Windows Live range of online services and allows users to keep the files private, share them with contacts, or make the files public. Publicly-shared files do not require a Windows Live ID to access.
The service offers 25 GB of free personal storage,with individual files limited to 2 GB (300 MB via the web). The service is built using HTML5 technologies, and files can be uploaded via drag and drop.