Use sprites as score/GUItext?

This is probably a late answer, but anyway here is how I do it. You need to have your score sprites named "0", "1", ... "9" in the game somewhere outside of the camera view otherwise this code will not work.

This code can be improved further for better performance.. but I for my game it is unnecessary since I don't have too many objects on the screen.

 public class ScoreManager : MonoBehaviour {
 
         private const float SPRITE_WIDTH = 0.07f;
         private const string SPRITE_TAG = "SCORE_SPRITE";   //http://answers.unity3d.com/questions/33597/is-it-possible-to-create-a-tag-programmatically.html
 
         void Start() {
 
         }
     
         public void UpdateScore (int score) {
 
             //remove previous scores
             GameObject[] oldScoreDigits = GameObject.FindGameObjectsWithTag(SPRITE_TAG);
             foreach (var oldScoreDigit in oldScoreDigits) {
                 Destroy(oldScoreDigit);
             }
 
             string scoreStr = score.ToString();
 
             for (int i = 0; i < scoreStr.Length; i++)
             {
                 GameObject digit = (GameObject)Instantiate(GameObject.Find(scoreStr.Substring(i,1)));
 
                 digit.tag = SPRITE_TAG;   //tag this object for easy removal
                 digit.transform.parent = this.transform;
                 digit.transform.localPosition = new Vector3(i * 0.08f, 0, transform.position.z);                
             }
             
             //center score to top screen
             Vector3 pos = Camera.main.ScreenToWorldPoint(new Vector3(Screen.width/2f, Screen.height * 0.96f, Camera.main.nearClipPlane));
             pos.x -= scoreStr.Length*SPRITE_WIDTH/2f; 
             transform.position = pos;
         }
     }

Put this script on a GameObject under your main camera. That way the score is always visible on the screen. As shown below.. this script is attached to Score game object under main camera.