Do you have any sites that have google caches that update 'intantly'.
 

As said in the title, do you have any sites that have their google cache updated instantly upon that site being updated?

Can you say "Google cache will update at 4:30GMT today" and then make it happen?

If so, what type of site (video/text/tube/blog/html 1 page wonder)?

How long has it been like this?