Network data transfer tests on 57,000 iPhones all over the United States show that, on average, AT&T iPhone data transfer rates are about 2 times faster than Verizon iPhone’s.

Wired reports:

Ookla, creators of the Speedtest.net broadband test, compiled data from tests run by iPhone customers using the Speedtest.net app on both AT&T and Verizon. On average, the reported AT&T iPhone transfer rates were roughly two times faster than the Verizon iPhone’s.

The AT&T iPhone’s average download speed was 1,769 Kbps, and the average upload speed was 730 Kbps. By way of comparison, the Verizon iPhone’s average download speed was 848 Kbps, and the average upload speed was 506 Kbps.

The results come from 43,000 AT&T iPhones and 14,000 Verizon iPhones all over the United States. Most Speedtest.net app users ran the tests multiple times, totaling 106,000 results from AT&T iPhone users and 49,000 results from Verizon iPhone users.

Wired also notes that in the reporter’s own tests, tests show that the Verizon iPhone is able to complete all tests while AT&T iPhones were not, leading to the conclusion that AT&T’s coverage isn’t as good as Verizon’s.

Of course, this may not seem like news to most people. AT&T has been notorious for dropped calls while Verizon continues to tout its broad and reliable cell phone coverage. In my continuing saga of cell phone shopping, I have to make a trade-off if I really want an iPhone. AT&T’s iPhone is faster than Verizon’s iPhone, but AT&T has poorer coverage than the Verizon iPhone.

The conclusion? Go with AT&T’s iPhone if you plan to use it primarily to surf the web and other online activities, but go with the Verizon iPhone if making and receiving quality calls is more important to you. What do you think?

I’m now entering my Nth week of cell phone shopping and researching the best mobile carriers. What’s important to me is being able to simultaneously talk and surf the net using my mobile. Furthermore, I like the option of using my cell phone as a modem for my laptop– aka “tethering” and is often listed as a “Mobile Hot Spot” service option.  So, if you’re looking for a new plan or cell phone, and you’re an email and Facebook addict like me, you may want to hear what I’ve discovered.

Each of the major carriers (AT&T, Sprint, T-Mobile, Verizon) have different Mobile Hot Spot (aka tethering) data limits, data plan pricing and simultaneous talk-and-surf capabilities. I called each carrier’s customer service lines and got the answers below (as of today). I recommend checking for regional differences. The type of cell phone you use may also affect capabilities including iPhones and Evos. I hope this helps!

AT&T (888-333-6651)

* Simultaneously talk and surf the web? YES

* Mobile Hot Spot: $45 per month for 2GB, $10 per additional GB

Sprint (866-866-7509)

* Simultaneously talk and surf the web? It’s complicated. Basically, if your mobile phone is 4G capable and you’re in a 4G area, then yes, you can simultaneously talk and surf the web on your phone. However, if you only have a 3G-enabled phone or are operating in a 3G-only zone, then you are NOT able to talk and surf at the same time.

* Mobile Hot Spot: $29.99/mo for unlimited data

T-Mobile (800-866-2453)

* Simultaneously talk and surf the web? YES- as long as you are using phones that are capable of simultaneous talk-and-surf such as the T-Mobile MyTouch 4G and the BlackBerry Curve 9300 (3G).

* Tethering: $14.99 per month for unlimited data

Verizon (888-333-6651)

* Simultaneously talk and surf the web? NO

* Mobile Hot Spot: $20 per month for 2GB, $20 per additional GB

The verdict is that T-Mobile has the best offer with only $14.99 per month for unlimited. However, T-Mobile’s mobile phone selection is limited. Of course, data transfer speeds vary by mobile carriers and that may be another trade-off to consider when shopping for a new cell phone or cell phone plan. Also, pricing and limits are subject to change by the carriers.