I was curious if there is a way to fade a texture in and out without using GUI.DrawTexture?
You can script a change in the alpha channel of your guiTexture. I use iTween.ValueTo for this, but you could also use a Mathf.Lerp. (iTween also has FadeTo and FadeFrom functions, but as I’ve never used them, not sure if they would solve your problem.)
http://itween.pixelplacement.com/documentation.php
http://unity3d.com/support/documentation/ScriptReference/Mathf.Lerp.html
guiTexture.color.a = Mathf.Lerp( from, to, whatever);