Here a screenshot:
What you see here is an OpenGL-SDL based GUI from my own kitchen. In the background there is a skeletal animation of a 3D model using the Cal3D library.
So far I've coded MenuBar, Context Menu, Dragable Window, Textbox, Checkbox, Button and Label controls. It makes use of VBO for everything and it supports reloading of video resources on display mode change.
Oh and loading of Themes on the fly!