Yes it is done. Both as small scale and large scale projects:


http://www.iht.com/slideshows/2007/0....0211niger.php

http://en.wikipedia.org/wiki/Deserti...esertification


If I may change focus from fact to fiction I would suggest you read the Dune series of books by Frank Herbert. Dune is a desert planet with absolutely no open water. Over thousands of years it is turned into a green planet and then into desert again.