MonoBehaviour.Invoke  

// Launches a projectile in 2 seconds

var projectile : Rigidbody;

Invoke("LaunchProjectile", 2);

function LaunchProjectile () {
var instance : Rigidbody = Instantiate(projectile);
instance.velocity = Random.insideUnitSphere * 5;
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
public Rigidbody projectile;
void LaunchProjectile() {
Rigidbody instance = Instantiate(projectile);
instance.velocity = Random.insideUnitSphere * 5;
}
void Awake() {
Invoke("LaunchProjectile", 2);
}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

public projectile as Rigidbody

def LaunchProjectile():
instance as Rigidbody = Instantiate(projectile)
instance.velocity = (Random.insideUnitSphere * 5)

def Awake():
Invoke('LaunchProjectile', 2)