Also: :-)
http://archive.ncsa.uiuc.edu/Cyberia/NumRel/GenRelativity.html
http://archive.ncsa.uiuc.edu/Cyberia/NumRel/GravWaves.html
And finally here was another fun thread where we argued the speed of gravity.
http://www.freerepublic.com/focus/f-news/1177535/posts?page=1,50