This blew my mind.
I submitted a topic on my message board to ask someone to preview a layout for me in mac. And about five minutes later I did a google search on “preview layout in mac,” that thread showed up in the first page of the search results.
UN……REAL!
Pure-Essence.Net 
You can check how often Google *re-crawls* existing pages using seometer tool. Thought you might be interested.
Wow… that was fast. Yay for DMB.