I just thought I would share what happened to me recently when an app I use left a comment on a wordpress site that had a "recent comments" widget. ~4800 no-follow backlinks! All from one comment that says something like "thanks LINK". The first day I got 700, and it took me by surprise. Then 1.5k the next day, then 300 and it kept going like that for a week. I've since dropped off the list so they should start disappearing. No sweat as they are no-follow. There are only the most recent 3 comments on the widget. I'm not quite sure how to use this to my advantage - anyone? Maybe this can be a warning about having it on your own site. You might end up with thousands of links to spammy sites just with this little widget if you have a large site.