Yes OpenGL extensions are great, and Im using some here and there but… where I can find a complete list of PRACTICAL EXAMPLES on how to use them?
nVidia has an SDK and individual samples can be downlaoded
http://download.developer.nvidia.com/developer/SDK/Individual_Samples/3dgraphics_samples.html
Same thing for ATI.
The Khronos/ARB group will put out a SDK from its own site someday.
where I can find a complete list of PRACTICAL EXAMPLES on how to use them?
What do you mean by a “practical” example? What’s the difference between a practical example and an impractical one?
PRACTICAL EXAMPLE: Example that show me how to use the extension(s) and present me piece(s) of code that can potentially be added into an application… 
There is no list for all extensions 
You may find some examples by using google with the name of the extension. Some newer extensions introduced the habit of adding an example section in the extension specification.
PRACTICAL EXAMPLE: Example that show me how to use the extension(s) and present me piece(s) of code that can potentially be added into an application…
Therefore, any example will do?
Leave it Korval, the guy’s obviously a bit tapped.
years ago on my site i wrote a small demo with various opengl extensions (my goal was to do them all) i have the following, which i can email if u wish, bear in mind i wrote these in 2000 so the code style is prolly crap