Try one of the quotes modules. Make the module/block visible for anonymous but not for registered users. Add some quotes.
The easy way : Create a block with custom content and make it visible for anonymous but not for registered users. That will show static content to anonymous users.
Another way: Create a block with custom content (HTML) and make it visible for anonymous but not for registered users. Add the script from here (change only quote 1, quote 2 or add some more if you need so)