You could try the SF Match website as a starting point. It has a lot of fellowships listed. It's definitely not an exhaustive list by any means, but it's definitely a start. It even has some private practive fellowships.
most fellowships are at http://sfmatch.org/
but there are also a lot of non-match fellowships out there which aren't on that website.
Plastics fellowships are on a different website too I think
there is a public directory you can look at without registering. It doesn't have much info about the program, it just lists them & has a couple of facts