Since I am a happy Steripen user, I've been wanting a lighter 1 liter wide-mouth bottle ...so I ordered one of the new "ultralites", and my kitchen scale says:
Ultralight Nalgene - 3.5 oz
Regular Nalgene - 6.3 oz.
So, a bit of a weight savings...I'll take it! For some mysterious reason, I did not find the product weight on Nalgene's website, and REI