it gives you air play and makes it harder to jailbreak
Yes. If you update your iPhone's software using iTunes it will lock your iPhone again. You will then need to unlock it again.
plug your iphone into your computer and go into itunes click on your phone under devices go to summary and press check for update or update iphone.
Simple answer: Yes.Only update when the Jailbreak you use has a new version / then only update the Jailbreak, not the iPod/iPhone.
No.
The exact release date is 17th June 2009. To find out more go to apple.com/iPhone and you'll see info about iPhone OS 3.0 and the new iPhone 3G S. Which is the new iPhone with voice recognition and video recording.
Upgrading an iPhone will update the firmware (the iOS) and will therefore remove the jailbreak. If you wish to stay jailbroken, it is highly recommended to not update until news of a new jailbreak arrives for the upgrade.
What you do is you go and plug up ur iPhone to the iTunes and click on the update button
The update 6.1.6 helps to maintain the working efficiency for the iphone 3gs.
Update the software in iTunes and it will do it for you.
I don't believe the iPhone 3G can update past 4.2.1, but any newer iPhone can update the same way you normally update an iPhone through your iTunes authorized computer.
yes. the current update is 3.1.3 and to update to it you have to restore you iphone, update it then re-jailbreak it. but at this moment in time this is not an jailbreak for firmware 3.1.3.
Considering updating your iPhone forces you to update to the latest software available for the device, updating an iPhone 3GS now will update it to iOS 6.