I came accross this VERY handy plugin, just add it to Firefox.
[url]https://addons.mozilla.org/en-US/firefox/addon/secure-or-not/[/url]
Press CTRL SHIFT S on each page you want to check.
It puts red dashes around all of the non-secure content and green dashes around secured.
Great tool for those of us upgrading to SSL from a standard site.
I shall begin the conversion.
Hope it helps someone.
Thank you jhagg for the interesting link.