Addition to CollapsibleLists.js to support expand all, collapse all.

example.html

        <div id="floatingbar">
            <ul>
                <li><a href="#" onClick="CollapsibleLists.expand(true)">Expand All</a></li>
                <li><a href="#" onClick="CollapsibleLists.expand(false)">Collapse All</a></li>
            </ul>
        </div>

mod to CollapsibleLists.js

var CollapsibleLists =
    new function(){

        // skipping the good stuff...

        // Expands or collapses all list items depending on the passed value.
        // if open is true, then opens all list items, else closes all list items.
        this.expand = function(open){
            // find all li elements with class collapsibleList(Open|Closed)
            // and set per open flag
            var elems = document.getElementsByTagName('li');
            for (var index = 0; index < elems.length; index++) {
                var elem = elems[index];
                if (elem.className.match(/(^| )collapsibleList(Open|Closed)( |$)/)) {
                    elem.className =
                        elem.className.replace(
                            /(^| )collapsibleList(Open|Closed)( |$)/, '');
                    elem.className += ' collapsibleList' + (open ? 'Open' : 'Closed');
                }
            }

            // find all ul with class collapsibleList then
            // remove collapsibleList(Open|Closed)
            // then set per open flag
            // also change style for open to "display: block;" and
            // for not open to "display: none;"
            elems = document.getElementsByTagName('ul');
            var first = true;
            for (index = 0; index < elems.length; index++) {
                elem = elems[index];
                // check whether this list should be made collapsible
                if (elem.className.match(/(^| )collapsibleList( |$)/)) {
                    elem.className =
                        elem.className.replace(
                            /(^| )collapsibleList(Open|Closed)( |$)/, '');
                    elem.className += ' collapsibleList' + (open ? 'Open' : 'Closed');
                    elem.style.display = (open ? 'block' : 'none');
                    // The top level ul's display style must be 'block'
                    if (first){
                        elem.style.display = 'block';
                    }
                }
                first = false;
            }
        };
}();