There is a neat little open-source tool from the folks at Google that allows you to use Google Docs as a service, uploading and downloading documents from the command line.

From Google:

GDataCopier is an API for Python programmers to:

• Download documents and spreadsheets to various formats
• Upload documents and spreadsheets from various file formats to the Google docs system
• List useful information about documents on the Google servers

GDataCopier provides a command line tool called ‘gdoc-cp’ that allows
system administrators to automate bi-directional copy of document
between the local machine or Google document servers.

Read more here: http://code.google.com/p/gdatacopier/