All ICS devices have this feature. The standard Power+Volume Down method, some phones, including many Samsung devices, use Power+Home .
In both screenshots, navigate to: Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + "/Screenshots"
In some way, the path is still Environment.getExternalStorageDirectory() + '/DCIM/Screenshots'
Prior to ICS, some manufacturers introduced this feature with various keyboard shortcuts and a destination directory where screenshots are taken.
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