TER General Board
Frankly I just love the phrase "lascivious exhibition." Sounds YUMMY to me.
But seriously, I could be wrong but I believe that the 2257 law is really geared towards third party publishers of pornography. ie: A company hosting images of many models where they are buying the photos from different photographers or photography companies. NOT for someone posting pics of themselves.
I cannot imagine them coming after me and saying that I can't legally post images of myself... it would be an interesting thing to be sure! How will they say that I didn't consent to myself?!?
Anyways... if you are truly concerned you should probably ask a lawyer, or maybe one will chime in here. I personally am not going to worry about it... this law is being challenged in the legal system right now anyways and hopefully will get tossed out.
(I said HOPEFULLY. A girl can HOPE for some semblance of sanity, can't she?)
Good luck either way... 
Tamara
As I understand the law, it isn't that you can't post them whether they are of you or not.
It is that you must maintain records proving that the model is of age. To that end the webmaster, or the person that owns the site, etc. are supposed to keep records of all the models with their names, all aliases they have ever used, and copy of government issued ID stating date of birth...blah...blah...blah.
As to Miss Bishop's original query, genitals are external sex organs (ie male: penis, testicles; Female: labia, clitoris...) So I would say, breasts and buttocks would not be / are not included. As for whether or not your nipples are lascivious...that would be in the eye of the beholder.
Think tasteful / artistic as opposed to vulgar / pornagraphic type thing...so long as you aren't having sex, mastubating, or posed in such a way that one could study to be a gynecologist from your photos i think you should be fine.