Pulsations at cylinder valves that are associated with the cylinder nozzle resonance and residual, low frequency pulsations in the piping system beyond the filter bottles are the main pulsation problems that were identified at the start of the GMRC ARCT (Advanced Reciprocating Control Technology) Pulsation Control Research Project. Low or no pressure loss concepts were conceived during the research project that would reduce, and in some cases significantly reduce, the pulsations associated with those two main pulsation issues. Simulations were developed and prototypes were tested in an effort to evaluate and further develop the pulsation control concepts. At GMC2006, current progress was presented regarding the project prototype development. All the prototypes presented showed promising pulsation control characteristics. Some prototypes had characteristics that were more promising than others. The virtual orifice (VO) showed significant reduction of the cylinder nozzle pulsations without the cost of the pressure losses typically associated with an orifice. The tunable side branch absorber (TSBA) nearly eliminated low frequency pulsations over relatively large speed ranges. Advancements of those prototypes, other prototypes, and new concepts for the current year are presented in this paper.