function Start () {
    var r : Rect = guiTexture.GetScreenRect ();
    Debug.Log ("This gui element is " + r.width + " pixel wide.");
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Start() {
        Rect r = guiTexture.GetScreenRect();
        Debug.Log("This gui element is " + r.width + " pixel wide.");
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Start():
        r as Rect = guiTexture.GetScreenRect()
        Debug.Log((('This gui element is ' + r.width) + ' pixel wide.'))