yea, sit it out. a lot of people will probably say don't be a pussy, go ski, but spines are not something to be fucking with. now a broken femur, that's a different story...
is it a stress fracture in the little wings that come off the vertabrae? because that happened to me a couple years ago and I got an mri and stuff but the doctors said that theres nothing they can do about it. I just rested for like a week then i was skiing again with no pain.