LAN sent me an email about this fare and it sounds pretty good. They're a little cryptic about the restrictions and the taxes, so I figured I'd just toss it out for further investigation for those who might be interested.

http://www.lan.com/en_us/promociones...ol/miabog.html

I also recall there are some strange inter-continental mileage runs floating around, and perhaps this one way fare to South America could be useful in that endeavor.