Recently, I’ve been interested in factory unlocking my still on-contract iPhone 4S. I’d heard of various services over the past few months, but never really investigated them until recently.

After asking around on Twitter, I stumbled upon Cellular Medic — one of many services available online that claims to be able to factory unlock the iPhone for a fee.

I was pleasantly surprised that the entire unlock process took a mere 10 minutes. I went from an iPhone 4S locked to AT&T, to a permanently unlocked iPhone 4S that’s usable on virtually any GSM carrier. Take a look inside for a video walkthrough documenting the experience…

[tube]http://www.youtube.com/watch?v=YZKZognj-BY[/tube]

For the record, let me just say that there are many unlocking services available on the web, but Cellular Medic promised to have my iPhone unlocked within a very small amount of time — generally within 10 minutes using their “Instant” service. Granted, they did perform this unlocking service free of charge for me, as a means to test it out, but this should be fairly indicative as to what you can expect if you use their service.

Cellular Medic charges $75 for their “Instant” unlock, and $60 for their unlock within 24 hours. Again, there are other options out there on the web, and many on eBay that have a good reputation. Many times, you may even be able find similar services for even cheaper than what Cellular Medic offers.

Their process works like this for AT&T customers:

  • Visit their website, and choose the unlock — instant, or regular
  • Pay with PayPal, and include your IMEI number in the PayPal notes
  • Wait for a response from Cellular Medic via email to verify the IMEI
  • Your iPhone should be unlocked within the selected time frame

If you’re locked to another carrier besides AT&T, you still may be able to unlock; check their website, or contact them to verify. To find your IMEI number, open up the phone app, and dial the following code: *#06#

If you have an iPhone 4S, it’s as simple as popping out the current SIM, and replacing it with a SIM from another carrier. The iPhone will automatically go through the activation process.

If you have an iPhone 4, you will need to perform a backup, and then restore. During the setup process, your device will activate the SIM card from the alternate carrier(s).

The great thing about a factory unlock is that it is permanent, and requires no jailbreaks, special SIM cards, etc. It just works.

Again, check around the web, and perhaps even eBay, and see what works for you. Though, I can say that I’ve personally used Cellular Medic, and recommend them; they lived up to their claims.

Right now is probably a great time to start considering a factory unlock for your iPhone 4S, especially if you plan on selling it to get the next iPhone. For a small up-front investment, a factory unlock will command much more resale value on eBay or Craigslist.

Have you considered factory unlocking your on-contract iPhone? Have you already done so? Which service did you use, and how much did it cost? Sound off with your thoughts in the comments below.