Preventing iframe caching in browser

Question

How do you prevent Firefox and Safari from caching iframe content?

I have a simple webpage with an iframe to a page on a different site. Both the outer page and the

Answer 1

Make the URL of the iframe point to a page on your site which acts as a proxy to retrieve and return the actual contents of the iframe. Now you are no longer bound by the same-origin policy (EDIT: does not prevent the iframe caching issue).