Making an object a child on collision

Questions & Answers
1

Is there a script that will make an object a child of another when they are touching each other. only in contact, so when they are not touching each other my object is not a child of the other one

note i am new to scripting

2

This should work nicely: 

function OnTriggerEnter (other : Collider) {
    if(other.gameObject.tag == "objectYouWant") {
        other.transform.parent = transform;
    }
}

function OnTriggerExit (other : Collider) {
    if(other.gameObject.tag == "objectYouWant") {
        other.transform.parent = null;
    }
}

This is for when they are trigger's, if they aren't the use:

function OnCollisionEnter  (other : Collision) {
    if(other.gameObject.tag == "objectYouWant") {
        other.transform.parent = transform;
    }
}

function OnCollisionExit (other : Collision) {
    if(other.gameObject.tag == "objectYouWant") {
        other.transform.parent = null;
    }
}

Simply attach one of these scripts to the object you want to be the parent, then tag the other object accordingly. Just make sure you change the 'objectYouWant' tag.