2.55 Shadows

Can someone help me with GLSL Shadows in Blender 2.55 with an example file or tutorial.

ave you tried using Spot lamps and set its shadow type to Buffer Shadow.
http://www.screencast.com/users/blenderwho/folders/Jing/media/b156c267-0e69-4267-b3e1-895206554b5b
demo.blend (622 KB)