the Blogger Data API-example "blog this".

ex-ample:
Javascript Code of "Blog This!"
http://gdata-javascript-client.googlecode.com/svn/trunk/samples/blogger/blog_this/blog_this.html
It's 2 scripts:
script src="http://www.google.com/jsapi?key=YOUR_API_KEY"
script src="http://gdata-javascript-client.googlecode.com/svn/trunk/samples/blogger/blog_this/blog_this.js

The 1st is the account-Authenticating (in order to access to you blogspot for updating its content).
The 2nd scrip corresponds to a SVN linkt:
http://gdata-javascript-client.googlecode.com/svn/trunk/samples/blogger/

Some links:
https://code.google.com/apis/blogger/

The Blogger Data API allows client applications to view and update Blogger content in the form of Google Data API feeds. Your client application can use the Data API to create new blog posts, edit or delete existing posts, and query for posts that match particular criteria.
Here are some of the things you can do with the Blogger Data API:

• Add a running list of blog posts and comments to a site.
• Create a desktop application or plugin that allows users to create and post entries from the desktop.
• Create a blog aggregator application.

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http://code.google.com/apis/blogger/docs/2.0/developers_guide_protocol.html

Your client application can use the Blogger Data API to create new blog posts, edit or delete existing blog posts, and query for blog posts that match particular criteria.
In addition to providing some background on the capabilities of the Blogger Data API, this document provides examples of basic Data API interactions using raw XML and HTTP. After reading this document, you may want to learn more about interacting with the API using our client libraries by reading the programming-language-specific sections of this developer's guide.
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http://code.google.com/apis/blogger/docs/gadgets/gadgets_for_blogger.html

At Google, gadgets are simple HTML and JavaScript applications that can be embedded in web pages and other apps, including Blogger.
Every Blogger blog is a gadget container.
example:
http://code.google.com/apis/blogger/docs/gadgets/gadgets_for_blogger.html#ExampleGadget
http://code.google.com/apis/blogger/data/blog_social_example.xml
It's a very simple Friend Connect powered gadget that takes advantage Blogger's JSON API. The gadget displays the current post's comments and highlights the comment if it was made by the viewer's friend. When the gadget is embedded in a blog, it will match the blog's style because it inherits several skin parameters.