For those who can't wait for the fabled gdrive, this is worth a look, you get like an FTP style interface to gmail within firefox, I've found it useful for quick backups.
Gmail File Space
his extension allows you to use your Gmail Space (2 GB) for file storage. It acts as a remote machine. You can transfer files between your hard drive and gmail. This is similar to "Gmail Drive" on windows platform. Your gmail account looks like a FTP host and you can upload and download your files. After you install, you get an option called "GSpace" in your "tools" menu clicking on which opens the window for transfer of folders/files. Works great for photos and music files less than 14MB.