How can I get even heat from consumer gas stovetop burners? I have a 5 burner modern style gas cooktop (KitchenAid), 4 in standard positions, one big double in the center. 

4 of the burners are all the standard circular shaped and seems most of their heat just goes to the outside edge of a circular pot/pan. I've lost a few non-metal accessories getting used to it.

Most professional models use multiple circles or cross shapes that put heat in the center as well as out sides. 

Is there method or part to use that would get more heat into the pot bottom?
So this may not be exactly what you were looking for, but I purchased one of these cast iron heat diffusers to help "tame" the heat from the cheap-o gas stovetop in my college apartment. You have to take the time to heat it up, but it helps distribute the heat evenly.

Cast Iron Heat Diffuser on Amazon