If you want to insert in your iPhone other SIM card than the one from AT&T; first to have to unlock it and you can find many ways to do it. You can find many software unlocking programs on the internet that will guide you to the process step by step and if you pay attention of the instructions you will see that is very easy to unlock the iPhone 3g.

One of the software programs is iPhone Unlocking; this program unlocks your iPhone 3g, you can jailbreak it as well is you want to add knew applications to your iPhone, application you can’t find on iTunes Store.

After you used the software in a matter of minutes you can use whatever SIM card you want like T-Mobile, Orange or Vodafone. This software runs in any firmware version and it is able to find solution for iPhones that have been damaged or have been relocked because of the upgrading through iTunes.

This software helps you to keep the functionality and the features of your iPhone, doesn’t damage the software inside, enables instant messengers, enables GPS and Rss Feed. If you want to get back at your iPhone’s default setting, lets say for example you need to do that because you have some technical problems and you need the warranty to return the iPhone to the store, you can always to that in a matter of seconds.

This software comes with some free application you might probably need: SNES Emulator, Video Recording, Voice Recorder, MMS Messaging, Voice Dialling and many more. Free of charge you will have life time updates and a lot of ringtones and wallpapers.

The software can be used a Macintosh computers but also on Windows operating systems.

Other unlocking iPhone software can be found on solutioniphone.com; it provides you a complete tutorial and software to make the unlocking process very easy. It very easy to manage with, just fallow the instruction guide and in less than 10 minutes you will have you iPhone unlocked.

Applications like MAPS and YouTube will accept any SIM card you insert in it. You will also be able to use Exchange services and MobileMe and if you want to give your iPhone new applications you can download them from Apple Ap Store.

Don’t worry about Cydia and Insttaler applications, because these will be added to the iPhone in the installation process. So now you are able to customize your iPhone with everything you want from themes, new applications (Video Records or Voip for example) to new games.

Another way to unlock your iPhone can be found on yellowsnOw.net. This is where you can see step by step the process of unlocking your iPhone:

The first thing you should do is to install Yellowsn0w and Install BossPrefs from Cydia. The next step is to disable everything to have in BossPrefs. Then you must reboot the iPhone with the help of BossPrefs. You will see “lockscreen” on the screen and you must wait 1.30 minutes after you see this message. After 1.30 minutes you should take the SIM out the iPhone and insert it again. You must wait a moment before you turn on FlyMode from settings. After you turn in on, you must turn it off and the iPhone should be working.

Other software for unlocking your iPhone 3g can be the software developed by iPhone Dev Team. The process is completely transparent to the user, and it will be launched when your Iphone is switched on. After you will install the software from Cydia, you will come back at the main menu and then you must restart your Iphone with the SIM you want to use. After the iPhone starts again, you will see in 10-15 minutes the name of the new network operator. If it take longer than a minute for the name to appear you must remove the SIM card from the iPhone and then you must insert it again. The software they are using is also Yellowsn0w, presented below, but this is another way to unlock you iPhone using the same software. If is very important to know that for the software to work you must deactivate the PIN code from your SIM card. This is a bug that the software provides promise us they will fix soon.

Unlocking step by step:

-Â Â Â Â Â Â Â Â Verify the version of your baseband. For this you must go in Settings – General – About and see what type of Moderm Firmware you have on your iPhone. If you don’t have the 02.08.00 version you should make an update for version 2.2 from iTunes.

-Â Â Â Â Â Â Â Â If you are using some type of hardware unlocking SIM or a NEXTSIM remove it from your iPod

-Â Â Â Â Â Â Â Â The next step is to deactivate the PIN code from your SIM card, this means the SIM card shouldn’t ask you for your PIN code when you inserted back in your iPhone

-Â Â Â Â Â Â Â Â Next you must open Cydia or Installer and go in Manage – Sources – Edit – Add and add the next source http://apt9.yellowsn0w.com/. This is helping you install the yellowsn0w software program.

-Â Â Â Â Â Â Â Â The final step; return to the main menu and restart your iPhone with the new SIM card inserted.

After this restart the iPhone should be unlocked and ready to use.

These are some ways to unlock your iPhone, you can find some more on the internet. I don’t think there is a best way to unlock your iPhone, just a lot of ways to do it.