Prepaid service for your laptop.

When you phone is activated.
At telcel to activate dial *264 ask for english speaking operator, give any name and some address, ask for SMS/text service to be activated.
After that send a text message. The number to send to is 5050 the message to send is:

bat1 (that gives you one (1) day internet access and will deduct 49,- peso of your prepaid credit)

bat7 (that gives you 7 days internet access and deduct 199,- peso of your prepaid credit)

bat30 (that gives you 30 days and deduct 642,- peso of your prepaid credit)

Internet speed is fairly good and fast. I was myself often surprised at what remote locations I was able to twitpic.
To charge phone airtime buy prepaid AMIGO cards that come in 100,- 200,- 500,- peso

Be aware with the promotional crap they offer. Like a 500,- peso card gives you 1000,- peso airtime but you can use only 500,- of that for international calls and internet, the other 500,- only within the telcel network for phone calls. The 200,- card gives you I think 240,- airtime credit.

Credits get de-activated after 90 days i.e. if you buy and have some credit left - lets say 300 peso and come back after 5 month you cannot use. Top of with 100,- peso and you have 400,- credit back for 90 days from the day you topped account of.

To charge the phone dial *333 and punch the number from the card in. make sure you do it right. if you screw up 3-4 times it want take it anymore. You need to go to telcel office and get credit but is an nightmare to do......
You can select the language first time when you do

If you have GSM cellphone with NO SIM lock you can just change the SIM cards.
If you have Vonage USB stick phone and use internet / laptop with SIM card adapter you can use Vonage. Works fine for many of my friends visiting.

Europeans all have GSM phones all SIM, dont know on the US providers. I think t-mobile is one, no clue on others.
Again: GSM phone to change card need to have NO SIM lock in it that ties the card to phone and want accept others.
I have several prepaid just for that reason. use myself contract since cheaper and live here.

I understand north are more providers, down here it is telcel and movistar. I cannot recommend movistar.