Google has released a new utility called GoogleCL which allows users to use Google services via the command line.
GoogleCL was created in Python and has been released under the Apache license. According to ars technica, any user that wants to contribute fixes or improvements can submit their patches on the GoogleCL issue tracker.
GoogleCL will work on Windows, Mac and Linux. Before you can use it on Windows you will need to follow the guide developed by Public int, it will require you to download GoogleCL, the Google Data API, and Python. After you get everything setup you will need to supply the software with a username and it will supply you with an OAuth link that you can put into you web browser to complete the authentication process. OAuth is an authentication protocol that allows users to approve an application to act on their behalf without sharing their password.
Currently GoogleCL only works with Blogger, Google Calendar, Gmail Contacts, Google Docs, Picasa and Youtube. The command line tool doesn't work with search, Buzz or Gmail just yet but they are working on it. The google project page says, "We'd love to support more Google services with GoogleCL, but we're currently limited by the availability of gdata APIs. Before hacking in our own services, it's probably best if we encourage the gdata teams to add new services (and python interfaces to those new APIs) first."