How to make screen capture on Android phone?

Most Android phones in the market have built-in screen capture function. Lets take Google Galaxy Nexus as an example. In order to make screen capture using Google Nexus, you just need to press the power button and the volume down button at the same time. (2 position in the picture above)

Different phones may have different way to do so. For example, the Samsung Galaxy S II:

 You need to press the power and home button at the same time.

The phones from HTC also have their own method, for example, the HTC Sensation XE and XL:

You need to press and hold the power button first, then press the home button.

If I made any mistake, please let me know.