HTC One X
To take a screenshot or screen capture with the HTC One X, simply:
Hold down the VOLUME DOWN button and the POWER button for a few seconds. The VOLUME DOWN button is on the side of the phone on the right and the POWER button is on the top of the phone.
The phone will make the photo capture noise, and the screenshot will appear in the screenshots folder or in the gallery.
Alternatively, hold down POWER and HOME. HOME is the middle touchscreen button on the front of the phone.
Using this method, the screenshots will appear in the DCIM folder of the phone.