graphael-linechart-legend.js

            raph = Raphael([..]);
            chart = raph.g.linechart([..]);

            var labels = ["first variable", "second variable", "third variable"];
 	    chart.labels = raph.set();
 	    var x = 15; var h = 5;
 	    for( var i = 0; i < labels.length; ++i ) {
 	      var clr = chart.lines[i].attr("stroke");
 	      chart.labels.push(raph.set());
 	      chart.labels[i].push(raph.g["disc"](x + 5, h, 5)
 	                           .attr({fill: clr, stroke: "none"}));
 	      chart.labels[i].push(txt = raph.text(x + 20, h, labels[i])
 	                           .attr(raph.g.txtattr)
 	                           .attr({fill: "#000", "text-anchor": "start"}));
 	      x += chart.labels[i].getBBox().width * 1.2;
 	    };

Forked to make corrections so it can work with the new version of gRaphaël.