Anchor text link creation plug in

A few years ago, a friend of mine developed a 're-linker' script that effectively ran a cron job and indexed all of the posts on his blog, then sought out keywords and keyword phrases in the content and linked them to other sites, creating anchor text links in his articles. It was a great plug in and with a little revision could've been much more powerful. I'm thinking that in the years since somebody's built and refined a better version of that, but I can't seem to find it.

I've got 165+ sites built on MU and would like to find a script like this to do this for both internal and external linking. Anybody have any suggestions?