There are a couple of teachers who did this a couple of years ago and they have just written a book about it. They have a similar outlook as Ryan and I and I have enjoyed perusing their blog. You can check them out at http://www.dollaradaybook.com/.
Here are a couple of articles about a North Carolina woman who wanted to prove that you could eat healthily on a dollar a day: http://www.walletpop.com/2009/02/26/how-to-eat-decently-on-a-dollar-a-day/ and http://abcnews.go.com/GMA/story?id=7062440&page=1
Here's another gentleman who ate for $30 for a month:http://hungryforamonth.blogspot.com/2006_11_01_hungryforamonth_archive.html
Our daily total came to $1.94.
We added some steel cut oats with a few raisins for breakfast which was a real treat and we had lentils with our rice for lunch. Dinner was brown rice as usual...it's amazing how good it can taste!