Does tv out disable the iPhone screen?

[myminirocks]

Hey Guys, couple of questions for anyone with an iPhone 3G and uses the TV out feature.

First of all, when you plug the iPhone into the dock/cable to send the picture out to the tv, does the screen on the iPhone switch off?

Also, I am reading a lot of issues with TV out if you don't use Apple supplied cables, and the only dock that works is the 'universal dock' which funnily enough, does not fit the iPhone 3G. I know you can buy additional iPhone 3G adapters but anyway....

Also, in regard to the 'universal dock' I can't seem to work out how it is powered. Is it via USB? ie does it have a USB port on the back of it and then a standard USB cable to go from your computer to the dock?

Thx guys!
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