CutYourSim, the unofficial official service that offers permanent factory unlocks for a variety of devices, has started proposing factory unlocks for the iPhone 4S and other models.

The company gained in popularity last year when it was one of the first to offer that type of service, until Apple cracked down on them and similar services that had been flourishing all over the net, forcing them to stop their activity.

But it looks like CutYourSim figured out how to get around those restrictions, as the company announced this morning that it is now taking orders for official and permanent unlock solutions for iPhones…

We are very happy to announce that we just started a new service to unlock all iPhones from AT&T USA including the latest 4S.

This service is 100% tested by us and working but since we have only been able to test it for a short period of time we will still call it a beta service.

Price for this service will be 199.99USD. Turnaround will be set to 1-20 days due to the high demand of this service.

So far, the iPhone unlock service appears to be available for AT&T iPhones only, but it’s probably a matter of time until CutYourSim offers unlocks for other carriers as well.

Wondering how a permanent iPhone unlock works? Simply explained, your IMEI is added to a database of iPhones that are “whitelisted” by Apple as officially unlocked. Once your iPhone IMEI has been added, just restore your iPhone in iTunes, and during the activation process, your iPhone will talk to Apple who will verify that it is officially unlocked.

This means that CutYourSim probably has an insider at AT&T (or an AT&T affiliate) who can add IMEIs to Apple’s database of officially unlocked iPhones.

Selling for $200, CutYourSim’s unlock offers a better deal that Apple’s own officially unlocked iPhones, who retail for $450 more than iPhones on contract. And seeing how we don’t seem to go anywhere with a software unlock such as UltraSn0w these days, this might be your best bet if you really need an unlock.

A couple hardware unlocks have also been surfacing these last couple weeks. Gevey Ultra S and R-SIM are two that come to mind, although there are probably more. Obviously, an official unlock as offered by CutYourSim is the most desirable one as it is permanent, stable, and doesn’t require any tooling around.

While I never tried CutYourSim myself, I’ve heard many positive reports about them. If you’re looking for a reliable and permanent unlock, give CutYourSim a try before Apple gets on their case again.