Materialize an object, then destroy it.

I need an object to appear as player walks into a trigger. So basicly I am asking for just one line of a script to make an object materialize in front of a player and then to be destroyed. Here is a reference to what I want to achieve.

public var AnObject : GameObject;

function OnTriggerEnter(other : Collider){
    if( == "Player"){
         yield WaitForSeconds(3);

The following should be an excellent read for you: