what exactly is unlocking and jailbreaking?

[dmhawk]

and, if i would like to do both to my iphone, which should i do first?

 

[reno55]

Unlocking is where you unlock the phone to use on another carrier other than ATT. In the USA the only other one would be T-Mobile. Unless you are traveling overseas or using T-Mobile then no you wouldnt need to unlock.

Jailbreaking is freeing the phone up to be able to install any 3rd party application...yes you would want to do this one so that you can have all the neat little apps that are out there.

 

[Cleverboy]

Jailbreaking is freeing the phone up to be able to install any 3rd party application...yes you would want to do this one so that you can have all the neat little apps that are out there.

WARNING: Many people tend to give poor advice on whether people should jailbreak their phones.

In February Apple will be adding official support for 3rd party applications. Until then, if you jailbreak your phone you are voiding your warranty, and if you intend to bring your iPhone in for service, would need to "RESTORE" it before doing so, or they will tell you the same. It is usually "poor advice" to encourage someone to do things without disclosing the consequences. For what its worth, Unlocking also voids your warranty, and moreover, depending on the type of unlocking you use, it could even damage your phone.

For most people, waiting until February is much better than opening themselves up to potential problems, and security risks. For others, they're interested in experimentation, and feel the benefits of using the fledgling apps that have come out in the last couple of months are worth the reward.

Personally I think there is a good thread about what people feel they get out of 3rd party apps on the Apple Phone Show Blog.
http://applephoneshow.com/index.php/archives/972

If you can wait 3-4 months OR you do not wish to risk your warranty support, DO NOT Jailbreak your phone.

If you really really need to use T-Mobile for some reason (maybe you really NEED a service that supports Fave 5 or something), then use iPhone Sim Free (the paid solution). It actually seems to provide good follow-up support, and gave customers a much more stable experience following Apple's 1.1.1 iPhone update. At that point, Jailbreaking isn't really an issue, as you've already voided your warranty (and you generally need to Jailbreak in order to UNLOCK).

Many of the applications available for the 1.02 iPhone firmware are being recompiled for the new version, so you should be good to go.

iPhone Sim Free
http://www.iphonesimfree.com/

App Tapp (1.02)
http://iphone.nullriver.com/beta/
App Tapp (Jailbreak 1.1.1 method)
http://www.iphonealley.com/news/iphone-v1-1-1-jailbreak-apptapp-installation-guide

None of this is for the faint of heart.

~ CB

 

[dmhawk]

thanks for the thorough responses!

i already have an at&t calling plan and phone, so i can just add data service to my account and use the iphone here in the US. my understanding is that activating my iphone via at&t will render my current phone's sim card inoperable, right?

my question is this:

-once the iphone is activated, will i be able to use the iphone's sim card in my older phone? (for situations when i don't want to be carrying around a $400 device in my pocket) EDIT: just tried it - the iphone SIM works in my old phone!

-when i go to another country, will i be able to use the iphone as a wi-fi device, or will it shut down when it doesn't find an at&t network?

i'm not particularly interested in using the iphone with a prepaid sim card outside of the US, since the data charges could be crazy $$.