Index: jquery/src/fx/fx.js
===================================================================
--- jquery/src/fx/fx.js	(revision 1304)
+++ jquery/src/fx/fx.js	(working copy)
@@ -301,7 +301,7 @@
 	 * @example $("p").animate({
 	 *   opacity: 'show'
 	 * }, "slow", "easein");
-	 * @desc An example of using an 'easing' function to provide a different style of animation. This will only work if you have a plugin that provides this easing function (Only 'linear' is provided by default, with jQuery).
+	 * @desc An example of using an 'easing' function to provide a different style of animation. This will only work if you have a plugin that provides this easing function (Only 'swing' and 'linear' are provided by default, with jQuery).
 	 *
 	 * @name animate
 	 * @type jQuery
@@ -379,7 +379,14 @@
 		return opt;
 	},
 	
-	easing: {},
+	easing: {
+		linear: function(percentage_elapsed, time_elapsed, value_start, value_difference, time_duration) {
+			return value_start + value_difference * percentage_elapsed;
+		}
+		swing: function(percentage_elapsed, time_elapsed, value_start, value_difference, time_duration) {
+			return value_start + value_difference * ((- Math.cos(percentage_elapsed * Math.PI) / 2) + 0.5);
+		}
+	},
 	
 	queue: {},
 	
@@ -558,8 +565,7 @@
 				// If the easing function exists, then use it 
 				z.now = options.easing && jQuery.easing[options.easing] ?
 					jQuery.easing[options.easing](p, n,  firstNum, (lastNum-firstNum), options.duration) :
-					// else use default linear easing
-					((-Math.cos(p*Math.PI)/2) + 0.5) * (lastNum-firstNum) + firstNum;
+					jQuery.easing["swing"](p, n,  firstNum, (lastNum-firstNum), options.duration);
 
 				// Perform the next step of the animation
 				z.a();