resize iframe height from remote URL

I'm pulling in content to a website from a remote website that is a
different domain. If the URL is on the same domain as my site, I can
use scripts like
<http://www.dynamicdrive.com/dynamicindex17/iframessi2.htm> to resize
the height. But because of javascript security reasons, I can't get
the height of the embedded content if it comes from a remote URL.

My goal is to provive content from one web site that can be embedded
into a second site, and exactly fit into a box on the receiving site.
The width is fixed, but the height will vary, depending on the content
and the local font size settings. I don't think this is going to be
possible with iframes (but please prove me worng!). Are there any
other ways I can accomplish this?