Black triangle observed from commercial aircraft passengers a short time out of Ft Lauderdale, FlaI was on a continental flight, a short time out of Ft. Lauderdale,Fla, I observed a very black dot above the clouds out the right side of the aircraft, it looked like it was expanding and became a very black triangle, it appeared to be several miles away. It seemed to not move for 3-5 seconds then turned to a black line going the opposite direction of our aircraft. I showed my wife the triangle and tried to get some pictures with our digital camera, but only show the black streak. The visibility was good and we were at 37000', I spoke to the pilot about it when we landed in Newark, but he did not see it or know anything about it.