Go to the institute that you are most interested in working with and look at the list of folks who have RO1 or R29 grants (these are PIs). Depending on where you are located, there may or may not be anyone with one of these grants.
You can also look into getting a position at NIH as a summer minority researcher where they can match you with a PI whose research most closely matches your interests.
Here's one that I found for Eastern Virginia Medical School. The PI is Howard D. White in the Department of Physiology who is doing research on Thin Filiment Regulation-Cardiac Actomyosin Hydrolysis. You would need to contact this PI and ask if he would be willing to write a supplement grant for you to work with him on some aspect of this research. You could look up his grant application (number is provided below) and see all of the aspects of this project. You would need to identify (with his input) some area that you could work on and how how much time you would be able to devote to the project.
EASTERN VIRGINIA MEDICAL SCHOOL 1R01HL084604-01 7086753 White, Howard D Thin Filament Regulation-Cardiac Actomyosin Hydrolysis PHYSIOLOGY SCHOOLS OF MEDICINE $331,400 NORFOLK VIRGINIA 23501-1980 Y EASTERN VIRGINIA MEDICAL SCHOOL NORFOLK, VIRGINIA 23501-1980 Domestic Higher Education N
I just looked up Virginia on this site
NIH Grant Money By State clicked on the state and got a list of projects by year. You would want to pick year 2006 as those projects are currently funded and working.
