hang-the-9 is pretty much on the money. Country Club in Chelmsford is a great place to play, but it's pretty far from Cambridge. The only public place in Cambridge with 9fters is Flattop Johnny's in Kendall Square, but you'll probably be disappointed since it's more of a bar than a pool hall; the tables are crowded together and too close to the walls.
If you're affiliated with MIT, however, and have access to the buildings, there may still be a 9fter in the Pritchett grill (2nd floor of Walker Memorial). And there is an offhand chance that there may still be a Gold Crown in the biology building (building 56) in the graduate student lounge. One of the former grad students was a player; he bought and put a GC in the lounge (tight pockets; Simonis) so he could shoot between experiments. He was having trouble selling it by the time of his graduation so he may have left it there (or maybe the university bought it off of him).
