Step 0: Sign up for foursquare if you have not already.
(This is not the same as signing up for foursquare. You need to click on this button to get the lamp to work for you.)
Step 2: Go to Park Slope, Brooklyn and make sure you are facing the window described above.
Step 3: Open foursquare on your mobile phone and check-in to the location called "LampSquare" to turn the lamp on or off.
All "lamp-ins" will be recorded on the @LampSquare twitter feed along with any comments you leave. Also, feel free to submit pictures or videos of your effect on the lamp to the LampSquare blog.