Show content with scrollbar?

The scrollviews should do that. It attaches scrollbars automatically, both vertical and horizontal, when the content's dimensions are greater than the containers. Take a look at the Controls tutorial, and scroll down to the part about scrollviews. It shows what they look like, and gives a code example on how to use them:

http://unity3d.com/support/documentation/Components/gui-Controls.html

It is copy by Unity script reference

 // The position on of the scrolling viewport
 var scrollPosition : Vector2 = Vector2.zero;

 function OnGUI ()
 {
     // An absolute-positioned example: We make a scrollview that has a really large client
     // rect and put it in a small rect on the screen.
     scrollPosition = GUI.BeginScrollView (Rect (10,300,100,100),
     scrollPosition, Rect (0, 0, 220, 200));
 
     // Make four buttons - one in each corner. The coordinate system is defined
     // by the last parameter to BeginScrollView.
     GUI.Button (Rect (0,0,100,20), "Top-left");
     GUI.Button (Rect (120,0,100,20), "Top-right");
     GUI.Button (Rect (0,180,100,20), "Bottom-left");
     GUI.Button (Rect (120,180,100,20), "Bottom-right");
 
     // End the scroll view that we began above.
     GUI.EndScrollView ();
 }

GUI.BeginScrollView