A Shocking Fall from Rankings

Corby's picture

I'm very surprised to see that http://delaflamme.org has fallen from its previously #1 ranking in Google search results to not even appearing in the first eight pages.

Now I'm wondering what site improvement I made that caused it. Was it moving away from the old URL that had /site/ in it?
Is it my new reliance on Posterous.com for posting?
Or is it changes in Google's algorithm? If this, then it isn't a very good change as households with sites unchanged for more than a year are now way ahead of this one.