Using Your Cell Phone
All major carriers have plans that now include voice calling in Mexico. We have AT&T "Mobile Share Advantage" and our plan includes unlimited calls, data, and texts in both the US and Mexico. Plan options change all the time, so before your next visit give your carrier a call to see what they're currently offering.
If your carrier doesn't include an inexpensive data plan, be sure to turn "cellular data" and "data roaming" off while you're still in Arizona. There are a few spots in the desert before Lukeville where my phone found it easier to tap into the Mexican cell towers than the US ones. Another aspect of using your cell phone without cellular data is that you won't have access to your voicemail (nor any indicators of how many people called or left a message). For many carriers, incoming texts are free (even internationally), so change your outgoing message to ask people to text you instead of leaving a voicemail.
Many resorts have shared WiFi available. Some have it in the condos only, some also have in the Lobby area, Pool area, and/or in their business center. Please see our chart of resort differences. These shared wifi connections aren't the same as what you're used to though. The trunk line which comes into the resort has bandwidth that is shared by everyone in the resort. So if the resort's busy, internet speed can slow down to a crawl.
Some individual condos have dedicated local DSL service, which is slow in comparison to the resort's fiber optic cable speeds. However, when the resort's busy, you won't be sharing the bandwidth with others.