Yea, it's either done with a really wide lens, possibly even a tilt/shift lens or view camera to keep things in focus (you get that type of distortion when you get a really wide lens really close, and there's a super cool chunk of math geek wizardry that explains how you can keep it all in focus by tilting the lens in relation to the subject and film, or digital sensor).
It also may be possible that they just stretched out the image disproportionally which could give a similar effect.
Smitty, the distortion in wide angle lenses is in proportion to both the distance from the camera and the distance from the center of the image. So the closer parts of the pen will be distorted more, and the closer parts are also more often than not near one of the edged of the image.
I'm in the middle of shooting a whole bunch of pens, so I'll drop on my 14mm and 10mm lens and shoot a few examples of similar distortion and post them...