Microsoft is updating its SkyDrive cloud storage service today to include document editing for non-Microsoft account users. In a blog post detailing the change, Microsoft's Omar Shahine also reveals that the service is now storing over a billion Office documents. The new Office Web Apps feature lets you to share a document to other users who do not have a Microsoft account, allowing them to edit and save anonymously. Microsoft says the feature is a result of requests from users, in particular students, that wanted to collaborate on documents in a group. The feature is live now and you can access it from the share menu within an Office document on SkyDrive.