Mark on wtc blog has documented a nice little technique to generate Technorati link graph. All you have to do is, just use the following URI to generate a PNG with incoming links to your blog for a given period using Technorati. There does seem to be a maximum number of days Technorati keeps track of links and that number is less than 365, closer to 200.

Note: Change the BlogURL value to the URI of your blog, and modify the size of the graph as you see fit for your blog or application.

 http://www.technorati.com/chartimg?q=BlogURL&days=3600&width=460&height=200&type=url 

Technorati, Links, Link Graph, Links Day Graph, Tips and Tricks