mexicotravelers.com is definately an awsome site.. .. . wish I had known about it before I forked out half a grand for my calls home.. .. . I had to learn the hard way.

I checked the site and cannot figure out what they are really selling, and there is no information on the site, so.. ..I am not sure of the last two posters are not affiliated with the site.

At any Telmex phone (they are EVERYWHERE) you can call the States or Canada for 50 cents a minute. This is how 90% of everyone calls home.
Buy a Ladatel card at any Six Tecate or most other stores, slip the card in the phone slot and dial away.

No need to purchase anything else or do anything else.
Ladatel cards come in 30 peso, 50 peso and 100 peso denominations.. .. ..use them and talk until the time runs out. The phone also have a buttom with ABC which changes the language on the LCD display to English.