Id like to let the user know that he can remove items from the legend by simply clicking on them. To some, this may be intuitive but others may not know that they can do tha
Highcharts doesn't have built-in tooltip for item legend, but still you can create your own tooltip for that. It's simple to add custom events to legendItem (mouseover and mouseout for example) and show that tooltip.
See example how to add events to elements in Highcharts: http://jsfiddle.net/rAsRP/129/
events: {
load: function () {
var chart = this,
legend = chart.legend;
for (var i = 0, len = legend.allItems.length; i < len; i++) {
(function(i) {
var item = legend.allItems[i].legendItem;
item.on('mouseover', function (e) {
//show custom tooltip here
console.log("mouseover" + i);
}).on('mouseout', function (e) {
//hide tooltip
console.log("mouseout" + i);
});
})(i);
}
}
}