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