Casey Lee from Joomlashack wrote a great extra for your Joomla template.
Read about this Extra on http://www.joomlashack.com/shack-team-blog/
Basically its some extra coding in you templates CSS and if you do it right it looks something like this:
This is a warning
Please take notice of this subject
If you get extra information is will look like this.
I am certainly going to use this more often, because I was looking for something like this for some time now.