If I unlock my iPhone 3G, what happens?

[npr031445]

Please answer step by step
1. What happens if I unlock my iPhone 3G?
2. I am planning to unlock my iphone 3g, but I will still use my AT&T sim card. I have 3g in my area, after i unlock it, will i still able to get 3g connection on my att sim card?
3. After i unlock it, will i able to update my iphone (ex: 2.1 to 2.2) without restoring my iphone?
Also 4. Do you prefer unlocking iphone 3g?
5. How do i unlock it?

6. DO I HAVE TO JAILBREAK IT FIRST?
7. DO I NEED TO RESTORE IT B4 UNLOCKING?

[Unregistered]

1.If you unlock your iPhone 3G you can switch networks, avoid data roaming, high resale value for the phone.
2.Yes, you can use it without any problem or losing any feature provided you take a genuine unlock service, like the one from Wickedunlock.com where they use permanent remote unlock service.
3.Yes you will be able to update the phone without restoring it.
4.Yes, I prefer unlocking because of its benefits and have experience in unlocking my phone through the mentioned unlocking site.
5.Through the mentioned unlock service provider.
6.No you need not jailbreak the iPhone to unlock it from the network.Jailbreaking allows a user to install third party applications, software, themes and removes the limitations that are on the apple device. In short it gives the user the root access to iOS.
7.No,that is not needed.You can gthrough the free unlock instructions for more details.