Microsoft has opened Windows Live Skydrive for beta testing. (During development it was known as Windows Live Folders.) It’s a place to store up to 500Mb of files online for storage or sharing. Many companies offer similar services but perhaps this will stand out; it offers the comfort of Microsoft’s brand name and lately Microsoft has been doing a good job of putting an appealing and simple interface on its products.

It’s possible to set up folders that are private, folders that can only be accessed by invited guests, and folders that are public. The interface is intuitive – similar to FolderShare – and you can install a small ActiveX control in Internet Explorer that makes it possible to drag and drop files into the online folders.

Skydrive is currently free; when it’s finalized, I’d guess that some portion of it will continue to be free, with the option to pay money for additional storage space.

Microsoft has built the service on its Windows LiveID/Passport authentication system. You’ll need to sign in with a free Windows Live ID, and you can only share files by using other people’s Windows Live IDs. Make sure you’ve got a working Windows Live ID before you try the Skydrive service!