UnicornSalesman, yes, the screenshot hack works on all Kobos -- but I wouldn't do it unless you're using a Sleepcover (because it takes over the function of the physical power button), and you won't have any other way to turn the device off or put it to sleep.
If you add the following lines below to the "Kobo eReader.conf" file, when you press the power slider it will take a screenshot (there's no feedback to let you know that it's happened -- just trust that it has; all it takes is a quick press/slide of the power switch). The screenshot will be saved as a PNG in the root directory of the device.
Code:
[FeatureSettings]
Screenshots=true