caching a page that was dynamically created ?

Say you have a page that you dynamically created with ajax calls and
RJS. Can you somehow get a copy of what that final page looks like and
somehow cache it away and later serve it from the cache ?

A problem seems to be that if you navigate away from a dynamic page
and then hit the back browser button, you can then lose the dynamic
content. I now you can have your own sort of back link, but I am
wondering what other things might be possible. You also can't bookmark
stuff that was dynamically created either. Whatever strategy you
employ effects the entire site, so that if you latter change it, you
have to change alot of code ..

You could save in the session (or the database) the current state of
the page and then use that information to re-render the appropriate
data when asked for that page again.