Will my phone work in Cancun? This depends on your carrier. The frequencies are 1900mhz, the same as US, so Most US phones will work in Mexico, while visitors from Europe will need a Tri-band phone. Most European carriers will have a roaming agreement with either of the GSM carriers in Mexico, which are TELCEL owned by America Movil, a Mexican company with networks around South America MOVISTAR owned by Telefonica, a Spanish company with networks in Europe and South America US CDMA Carriers Verizon and Sprint roam with IUSACELL, the CDMA network in Mexico, which I believe is the same network Cancunvalet subscribes to. I hear the coverage is OK around the hotel zone but patchy elsewhere. US GSM carriers ATT (formerly Cingular) and T-Mobile roam with TELCEL OR MOVISTAR. coverage on this network is good all down the coast to Playa del Carmen and beyond. IMPORTANT NOTE: You do need to setup INTERNATIONAL ROAMING on your phone BEFORE leaving home.In fact, it can take 3-4 days to get your account established on international networks so don't leave it to the last minute Beware of the difference between INTERNATIONAL ROAMING and INTERNATIONAL DIALLING Some carriers offer special plans for Mexico where you pay a small monthly fee for low cost calls. This in INTERNATIONAL DIALLING from your home netowrk, not INTERNATIONAL ROAMING on a foreign network. How much does it cost? It is free to enable International roaming on your phone, they just ding you for the airtime used when roaming. The actual rates depend on both your home carrier and the agreement they have with the Mexican carrier.Currently I believe the US carriers will charge you ATT www.wireless.att.com To simplify their terminology, it is based on Plans and Features (add-ons to Plans) International Roaming is included in your Plan and has no monthly charge but has to be activated at least 72 hrs before travel. Once activated it should remain activated but be sure to check if you change your rate plan, as it can sometimes get disabled. International Roaming costs $0.99/min whenever you are using air time in Mexico, including forwarding your incoming calls to you there. There is an add-on Feature to the plan called Discount International Roaming, Discounted Roaming Feature costs $4.99/month for Mexico/Canada, or $5.99/month worldwide. Cost per minute is reduced to $0.49/minute with either of the above, which is as cheap as using a local prepaid phone/SIM card T-MOBILE www.t-mobile.com $1.49/minute (or $0.99 if you opt for their "World Class roaming*" These rates apply to calls back to US from Mexico AND INCOMING CALLS. Local calls are cheaper, and calls to countries other than US from a US phone roaming in Mexico can be outrageous.For example, I once used my T-Mobile phone in Mexico to call Europe and got dinged $7/min!!! *The "World Class roaming" is not such a good deal, as they also charge you the Mexico rate according to your International Dialling plan for forwarding incoming calls to you on the Mexican network :evil: How do I dial home? International access code from Mexico is 00 (not 011 as in US), so to call US/Canada numbers is 00-1-xxx-xxx-xxxx Heres a tip, works with any GSM phone, (Cingular or T-Mobile). Just edit your stored numbers and in front of the "1" insert the + sign, usually by holding down the 0 key. Any numbers you store like that, can be dialled from your phone book, from any country,just like from home i.e. numbers in US and Canada need to be stored as +1 xxx xxx xxxx. You can also save any Cancun numbers you may need as +52 998 xxx xxxx. (+52 1998 xxx xxxx for mobile numbers) This does not affect making or receiving calls when you are back home, I store all my numbers that way and the caller ID works just fine. Can I send text messages? The GSM system is quite seamless and SMS text messages can be sent and received as normal. However, while roaming there is a cost per message which is not included in whatever bundle you pay while at home. I think it's around $0.10 or $0.15 per message. Now here's the rub. What makes the SMS system so interoperable, is that all messages go through a Service Center, which is a phone number programmed into your SIM card by the carrier. This is toll free while in US, but depending on the carrier policy, you may get charged for the call to deliver your text message in addition to the message cost. Currently, I believe T-Mobile charges for these calls, ATT does not. [ note to self- find out and update after I get my roaming charges from UK trip] Note: Some 3G phones may be set up to send text messages via IP or GPRS rather than service center. You will need to find how to set it back to use the service center or it may not work in roaming Can I send photo messages? Multi-Media messages (Photos etc) work differently, via IP or GPRS which is stored in the phone rather than the SIM card. It uses a carrier specific internet gateway and may not work at all.I have had no problem in using GPRS on Telcel for sending/receiving e-mail, but for some reason have never been able to send/receive photos. Currently, Caller ID between US and Mexico does not work at all. I have occasionally seen Caller ID come up here in US on my cellphone from cellphone numbers in Mexico but US numbers dont come through down there while roaming.