I think I post a link to this page on FT about once every two months on average:

http://www.nwa.com/travel/tips/baggage.html

To summarize...

Piece limits

• 2 pieces for coach (domestic or int'l)
• 3 pieces for FC or WBC originating from US
• 2 pieces for WBC originating outside US (I think that might be new)

Domestic weight limits

• 50lbs per piece non-elite
• 70lbs per piece elite

Int'l weight limits

• 70lbs per piece if itin involves US/Canada
• 44lbs total (not per piece!) if itin is wholly outside US/Canada (coach)
• 66lbs total (not per piece!) if itin is wholly outside US/Canada (WBC)