GMail Drive is a Shell Namespace Extension that creates a virtual filesystem around your Google Gmail account, allowing you to use Gmail as a storage medium.
GMail Drive creates a virtual filesystem on top of your Google Gmail account and enables you to save and retrieve files stored on your Gmail account directly from inside Windows Explorer. GMail Drive literally adds a new drive to your computer under the My Computer folder, where you can create new folders, copy and drag'n'drop files to.
With GMail Drive you can easily copy files to your Gmail account and retrieve them again.
When you create a new file using GMail Drive, it generates an e-mail and posts it to your account. The e-mail appears in your normal Inbox folder, and the file is attached as an e-mail attachment.
You can download GMail Drive from Softpedia.