How can I scale the content of an iframe?

Question

How can I scale the content of an iframe (in my example it is an HTML page, and is not a popup) in a page of my web site?

For example, I want to display the content

Answer 1

Thought I'd share what I came up with, using much of what was given above. I haven't checked Chrome, but it works in IE, Firefox and Safari, so far as I can tell.

The specifics offsets and zoom factor in this example worked for shrinking and centering two websites in iframes for Facebook tabs (810px width).

The two sites used were a wordpress site and a ning network. I'm not very good with html, so this could probably have been done better, but the result seems good.