   Total reflection
  You know a transparent object like a lake or a pane of glass, when you look at it from big enough an angle from the surface''s normal, light is totally reflected. How would you guys implement this in OpenGL?  
  That''s called the Fresnel effect. Generally speaking, the Fresnel term gives the reflection to refraction ratio, depending on the view angle and the surface normal (simplified). Usually, vertex or pixel shaders are used to compute that coefficient. Search the ATI or nvidia developer sites, they both have examples covering this.;  Thank you for pointing out the name, now I know where to look! 