Some information about the (still unofficial)  google reader API and how to use it:

• The Shallow Thoughts of a Simple Mind » WordPress Google Reader Plugin
  I have wanted to display items marked as “shared” from my Google Reader on my blog for a while and today I finally sat down and wrote a plugin to do it.
  (tags: software wordpress plugin googlereader)
• Google Reader API
  Google Reader is an online feed aggregator with heavy use of JavaScript and pretty quick loading of the latest feed data from around the web. Google’s AJAX front-end styles back-end data published in the Atom syndication format. The data technologies powe
  (tags: api google reader unofficial)