NVIDIA has released two SIGGRAPH 2008 presentations about CUDA. The first one talks about image processing and video algorithms with CUDA and shows some CUDA applications such as image filtering (sobel filter with code sample). This presentation talks also about NVCUVID, the video extension for CUDA. NVCUVID is similar to DXVA API, but is platform OS independent.
The second presentation is more general about CUDA programming and shows how to create high performance code to run on the millions of CUDA-capable GPUs already in use.