Check out David Bucciarelli's very impressive little OpenCL demo SmallptGPU2 (get it, with source code!, from his web site: OpenCL Toys.). It was developped using ATI Stream SDK v2.0.
See this YouTube video animation which I created using SmallptGPU2:
OpenCL path tracing renderer testing, animation (and Bullet Physics)
(David also has demonstration videos on his channel)
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