var myMesh : Mesh;
var oldScaleFactor : float;
var origUV : Vector2[];

function Start() {
    myMesh = GetComponent(MeshFilter).mesh;
    origUV = myMesh.uv;
}

function ScaleUV() {

    if (scaleFactor != oldScaleFactor) {
        var newUV = new Vector2[ origUV.Length ];
        for (var n = 0; n < origUV.Length; ++n)
        {
            newUV[n] = origUV[n] * scaleFactor;
        }
        myMesh.uv = newUV;
        oldScaleFactor = scaleFactor;
    }
}