From august 26-29, you can buy LANPass kilometers for 1/2 price (.01c/km), maximum 100,000 for $1000. Dan has a lot of information about LAN, I have used them once to book an award ticket from chile to USA. availability was decent, there was i think $50 booking fee (same as american).
LAN is in the American/British airways alliance (dont remember what it is called). I dont know how kilometers convert to AA miles for partner booking, maybe someone else can clue me in?
I really dont know if this is a good deal or not. You can buy straight up a roundtrip ticket from, say, Miami to Santiago for $750 (700$ for the kilometers + $50 booking) which is a pretty good price compared to retail. dont know about europe or easter island.
http://www.lan.com/es_cl/sitio_personas/promociones/lanpass/20100816_venta_kms.html?otid=257405&s_cid=lp_interno_20100826_vitrina_cl_ventakmsEdited to add: USA-Brazil is only 48.000 kilometers round trip, so thats $480+$50 for a round trip to brazil, which seems to be the best deal from what I can tell (especially since LAN has no fees for changing dates and has loose restrictions). Although I think it might only work if you are in one of the airports from which LAN flies direct (dont know about this). LAN also had a 1/2 price deal in april 2009 for 2 days, so maybe this is a once a year type of thing.