Which Carriers, Networks, Or Sim Cards Work With CECT iPhone Clones

I often have questions about which carriers or networks will or will not work with the CECT phones. Some examples are: "can I use the i9 with Verizon?;" "will the iClone work with metro PCS?;" or can the KA08 work with boost mobile?" etc. I'll try to address these concerns in the following article.
Which Carriers Or Networks Use GSM Sim Cards?: The simple answer is that any network that uses a GSM sim card will work with any CECT phone. Examples are T Mobile, AT&T, Fido, Rogers, and Cingular. There are others but these are the most common. Also, it really doesn't matter whether the sim is tied to a monthly plan, a prepaid plan, or a pay as you go option. T Mobile To Go or Flex and AT&T's Go Phone and Pay As You Go all work just fine too.
Which Networks Don't Work: All of the CDMA networks aren't going to work no matter what settings you try to use or what information you plug into the phone. They use technology that is not compatible with the CECT phones. And, networks like Boost Mobile, Metro PCS, Verizon, Sprint, Nextel, Virgin Mobile, and Alltel fit into this category.
Tracphone and Net 10 do use sims and I have actually had people tell me that they've gotten this to work. However, I tend to doubt this because it's my understanding that these network's cards will only work on tracphone or Net 10 phones.
Troubleshooting: Sometimes, I have people who email me and say that they ARE using T Mobile, AT&T, Cingular, etc. and still, the phone doesn't work. There are a couple of things to look for in this case. First, the card must be activated prior to your trying to use it. You can often do this online with the carrier or by calling a customer service number.
The second thing to check out is to make sure that you have the cards property installed. The slot on top should have the underside of the card facing down. The slot on the bottom should have the gold underside of the card facing up, sort of like the cards are forming a sandwich.
Sometimes, people will only want or need to use one card. In this case, you should go into "dual sim settings" in the phone and close off the card that you aren't using. You do this by just checking number one of number two, depending on where you've put the card.
Many people are worried about this issue because, although they don't mind switching carriers or even going prepaid, they don't want to lose or have to change their cell phone number. Most all carriers will give you your old number when you activate the card. Most times, you just call customer service and tell them your old number. Then they will check and confirm that it's yours and then set this up for you.
If you already have a GSM carrier that you are happy with, you can just take the card out of your old phone and put it in the new one. But, if you don't have data or Internet associated with it, you'll have to either add it through the company or buy a data sim (some are prepaid) to use in the other slot.
Right now, I would say that the two most popular iPhone clones are the CECT i9 and the CECT KA08 (if you want a mini or smaller model.)