I can understand the Gmail mania of these months, the growing number of applications and tools to provide better services with a Gmail account, but something like this is really impressive... GmailFS, a Gmail Filesystem.
What is it? It's an application for Linux that provides a mountable Linux filesystem which uses your Gmail account as its storage medium. It's written with Python and uses the FUSE userland filesystem infrastructure to help provide the filesystem, and libgmail to communicate with Gmail.
This is cool because GmailFS supports most common file operations (read, write, open, close, stat, symlink, link, unlink, truncate and rename), so you can use all your favourite Unix command line tools to operate on files stored on your Gmail account. You can normally mount your Gmail filesystem and start working with it.