Just wanted to give a little update on my test with this plugin. In the past 5 days I've seen an increase of ~1000 backlinks (in Y!SE) and the blog has dropped from its #7 position for the main keyword to #58. I'm going to continue testing as this could either be the result of Google quickly catching on or simply the Google dance due to the increase in links so quickly.
It's still free. Scrol down just past the green box and there is a field for your email which will generate an API key. Then right below that is the link for the free download.