I have my blog (you can see it if you want, from my profile), and it\'s fresh, as well as google robots parsing results are.
The results were alarming to me. Appare
"googleon" and "googleoff" are only supported by the Google Search Appliance (when you host your own search results, usually for your own internal website).
They are not supported by Google's web-search at all. So please refrain from doing that and I think that should not be marked as a correct answer as this might create ambiguity.
Now, to get Google to exclude part of a page, you will need to place that content in a separate file, such as excluded.html, and use an iframe to display that content in the host page.
The iframe tag grabs content from another file and inserts it into the host page. I think there is no other available method so far.