multi toch GUI buttons

It is possible, but you'll need to make your own buttons
Use GUITextures, and use the GUIElement.HitTest method to test if any touches are, well, touching them :D
(You'll need to iterate through all of the current touches)
Example script: var texture : GUITexture;

function Start() {
texture = gameObject.GetComponent(GUITexture);
}

function Update() {
for (var t : Touch in Input.touches) {
if (texture.HitTest(t.position, Camera.main)) {
//do something
}
}
} Just add that script to all your GUITextures that you want to act as buttons, and replace the "do something" comment with what you want the button to do :)