How do I unlock my iPhone 3G so that it can work with another carrier?

[IrvineCA]

I'm being screwed by AT&T and their rate plans for the iPhone 3G. Is there an effective way to unlock my phone so that it can work with another carrier like T-Mobile? I heard of this company called YESSIM that makes sim cards that can unlock the iPhone 3G. Any thoughts on this? Your input is highly appreciated.

[sree3]

Here is my experience about unlocking an Iphone 3G..for iphone there is no unlock codes but instead we can do it by remote unlocking..there are many online providers who provide the service..i got unlocked his iphone from Simpleunlocking by remote unlock..and the important thing remote unlocking is available for some country and network providers only so if you are interested you can try from them before that see whether remote unlocking is available for your country and provider..