and i am also not an expert and definitely less knowledgeable than you, rkkwan, but it seems to me that saving 1.2% repeatedly would eventually add up to real money. Same thing with not burning the fuel.

Actually when AA changed their domestic weight limits a couple of years ago - the explanantion was that it is safer for ground crew not to handle heavy bags. Had nothing to do with fuel prices, cargo load etc. And for a few weeks to months after, made some extra $$$ in overweight fees. Not surprised at recent change in international flights too. Each airline is allowed to set it's own limits and I would assume most US carriers will match AA [if they haven't already - Delta may have actually done it before AA]. Foreign carriers may be more lenient but if you connect to them using a US carrier, well - you know the drill.

If you really need extra weight in your baggage, you can go up to 70 lbs and it only costs $25 [which may be cheaper than a shipping charge].

Magellan's catalog is now selling a handheld utility scale for weighing your luggage. It sells for $9.85 - however I just went to my local sporting goods store and bought an identical scale for weighing fish - it was $6.99 and reasonably accurate. It goes up to 50lbs and would go in your carryon if you wanted to weigh luggage before flying home.