The Line Diet (good name!) is a web-based version of the Steve Ward Diet. There is also an (unrelated) iPhone app. From the site's creator:
About 4 weeks ago, I stumbled across a story on Kottke's Blog about the "Steve Ward Diet". The idea seemed ingeniously simple to me... so I started my chart the same day. I've lost almost 8 pounds since then.
Update: There's an Excel spreadsheet version as well.