You can take video using iPhone 3G using Cycorder which is available for free, but to do so require that your jailbreak your iPhone 3G. You can also spend your money on the iPhone 3GS so that AT&T can laugh up your money and continue to provide horrible services.
This depends on the interpretation of the question. iPhone 3G has a camera that is capable of taking both video and still image, but Apple has limit the iPhone 3G camera to only taking still image. It is possible to take video on the iPhone 3G using Cycorder, but doing so require you to jailbreak your iPhone 3G.
Install Cycorder, which is free, on your jailbroken iPhone 2G or iPhone 3G allow you to record video using your iPhone.
The iPhone 3G already have a camera that is capable of recording video. The inability to record video on the iPhone 3G by default is a software limitation rather than hardware limitation. To record video on an iPhone 3G, simply jailbreak your iPhone 3G and install Cycorder.
Simply jailbreak your iPhone 3G or iPhone 3G and install Cycorder.
I don't think the 3G records video.
iPhone 2G, iPhone 3G, and iPhone 3GS all have camera that is capable of recording video, however, Apple impose limits on the iPhone 2G and iPhone 3G that disallow video recording, in order to promote the more expensive iPhone 3GS. To record video on iPhone 2G or iPhone 3G, one must jailbreak one's iPhone and install Cycorder, which is available for free.
All iPhones can play video, but only the newest iPhone 3G s can record video.
the i phone 3gs shoots video
Yes.
about 10 hours
Yes, simply sync it using iTunes.
A regular iPhone 3G (not the 3G S) costs about $99, give or take some depending on where you buy it (not including tax).