Here, in the NE, dry basements (and that's a relative statement ...), are still finished with poly on the FINISHED side of the studs. By placing the poly on any where else, you may end up with a moisture problem you didn't have.
'Dry Basement' is the operative word. Assuming you have one, then a vapor barrier isn't necessary. HOWEVER, you'd still want to vent whatever moisture there is coming from the 'outside'. To do this, you basically build your finished wall an inch or so AWAY from the outside wall (to leave an airspace), then vent it INTO the finished basement. From there, you install a dehumidifier to get rid of whatever little moisture there is. If you were to install multiple layers of poly, you'll end up trapping moisture and causing problems down the road.
There's a very good article on how to finish a basment w/o poly in a recent issue of Fine Homebuilding Magazine (by Taunton Press). Search our Forum here for 'barrier' and read the Follow-ups. You'll get good info that way.