This looks like an awesome plan! I am also planning on doing something similar but starting in the US in Summer 2011 and then over to Europe for a couple of years before making my way back for South America over 3 years or so. So I will be paying much attention to your story. As far as your ideas for work go I also plan on doing a TEFL course before I go. In case you have not seen it yet check out http://www.wwoof.org/
. I met a girl from Utah when I was living in Ireland who lived and worked on Irish farms for about 8 months and it worked well for her.