Google Data interface is now supporting open OAuth stardard, this makes accessing information in Google property much easier.
What’s OAuth?
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OAuth is an open protocol to allow secure API authentication in a simple and standard method from desktop and web applications.
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To find out more, please visit OAuth website.
The Google Data APIs Blog also gives you information on how to start using the application.
GData ( short for Google Data API ) allows users to access information stored on most of Google products. Picasa, contacts at Gmail and Google Finance are just a few examples that you can retrieve information from and display on your website.
This simply gives some site administrators to have a second option to store the information required in Google, while they don’t have enough space to store all the information needed on a single server.
GData also supports two-way communications, which means you can update your contact list or add photos to Picasa through the API.