To capture what is currently being displayed on the screen of an iOS device, commonly referred to as a "screenshot", hold down the power button and press the application button. The screen will turn momentarily white and the camera sound will play.
The screenshots are saved to the Photos directory. From there you can review them, upload them to your computer, or email them to yourself or others.
References: A couple of articles with more instructions and screenshots...
How-To: Take iPhone or iPod Touch screenshots!
How to take a screenshot of your iPad
The screenshots are saved to the Photos directory. From there you can review them, upload them to your computer, or email them to yourself or others.
References: A couple of articles with more instructions and screenshots...
How-To: Take iPhone or iPod Touch screenshots!
How to take a screenshot of your iPad