Ke-Sen Huang has assembled a web page with links to all papers presented at these two important conferences, High Performance Graphics (a synthesis of the Graphics Hardware and Interactive Ray Tracing conferences) and SIGGRAPH. Both conferences had quite a number of GPGPU-related publications. Highlights from HPG include a paper on computing minimum spanning trees on the GPU, one on optimizing stream compaction on GPUs, and a study from NVIDIA on understanding the efficiency of GPUs and of wide-SIMD architectures in general on inherently imbalanced workloads like ray tracing (among others).
Click here for SIGGRAPH papers, and here for HPG papers. Ke-Sen’s pages are also a good resource for other conferences in the field.