Pretty Geographical Selector - Multiple Countries and States

In need of a clean/professional multi-select checkbox form tool (using javascript or jquery) that will allow users to choose Worldwide, OR multiple countries and then multiple child-states (or one box allowing all states) within the country. This should be done with flags using a collapsable checkbox tree or a sidebar as shown in the below video. If you can think of a more eloquent design for this multiselect tool, please advise. Not all countries will have child-states, but I should be able to easily add and remove countries and states as needed using standard html. Output from form submission should be comma-delimited as a standard checkbox input string such as "MX,US-NY,US-FL" and options should be prepopulated with previously saved data in the same string format "CA,MX,US-NY,US-FL". Lastly, the user should not be able to select states and the ALL states box at the same time. All code should be clean/bugfree and work on all browsers that can run jquery. For a demonstration, please see: [login to view URL] for an idea of what I am looking for.