So I know this isn't possible because people would type "inappropriate" words on it, but I've seen that before some people have put a TextButton on a surfacegui, or can you Adornee a screengui to a brick?
I'm quite not understanding why you saying it's impossible because it is.
Just insert a "SurfaceGui" into a brick and Insert a TextBox/Button/Label in it. <http://wiki.roblox.com/index.php/Beginner's_GUI_Tutorial#SurfaceGui>