I got my N900 in the UK with vodafone, while in Mexico I have been using a Telcel sim card but the internet never worked, I couldn't connect to it. I read somewhere here that Telcel used a different frecuency not supported by the N900.....well after updating to the latest firmware, the internet works flawlessly, the speed is not 3G but EDGE, but hey, I can't complain.

The N900 is not available at the moment in Mexico.