Coroutines with multiple arguments

What's the best way to start a coroutine that has multiple arguments. For example:

Code (csharp):

1. // plays an animation and sends a message when done.
2. function PlayAnimWithCallback(aAnim, aObject, aCallback) {
3.     if (!aAnim.isPlaying) {
4.         aAnim.Play();
5.         yield WaitForSeconds(aAnim.clip.length);
6.         aObject.StartCoroutine(aCallback);
7.     }
8. }

Using the following gives an error along the lines of: "no appropriate version of '...StartCoroutine' for the argument list (System.String, System.Animation, System.Object, System.String) could be found."

Code (csharp):

1. yield StartCoroutine("PlayAnimWithCallback", snakeStrikeAnim, gameControllerScript, "StrikeAnimDone");

 

You could pass an array, a dictionary, or your own special object with your arguements.