Check out this article: Samoa airline introduces pay-by-weight pricing - CBS News
No, this is not an April Fool's joke. Apparently Samoa Airlines is going to start charging 93 cents per kilogram. When you purchase your ticket online, they ask you how much you weigh and how much luggage you're taking. Then when you get to the airport, you step on a scale with your luggage, and I guess you pay the difference if you lied about your weight.
Everybody's up in arms about this (remember when Southwest Air said they'd charge a large passenger two tickets?), but I think these news stories are missing an obvious angle: TAKE LESS LUGGAGE!
If there was ever a reason to travel light and one-bag it, this is it. If I travel with just 14 pounds worth in my one carryon, imagine how much I could save compared to the person bringing heavy rolling uprights and check-in bags that total more than 60 pounds?