Booze:
You have to use either Photoshop CS or CS2 for this.
Open up your chosen image, press Q to switch to Quick Mask mode, then click on the Gradient tool. Set the colors to the default black and white by pressing D, then switch them around by clicking on the double-headed arrow next to the color chips. Next, set your gradient to "Normal" and 100% Opacity. Make sure you select the repeating gradient type – fourth icon along, looks like a cylinder.
Choose where you want the focal point of the photo to be – usually about halfway between top and bottom – and click and hold at that point. Drag the line of the gradient tool upwards, then release it towards the top of the frame; it doesn't hurt to be a little off the pure vertical. Press Q again to switch back from Quick Mask mode.
Chose Filter > Blur > Lens Blur to bring up the Lens Blur filter pane. It can take a little tinkering to get the settings just right. The Iris section controls the shape of the virtual iris in the lens; a hexagonal iris is most normal, and you could try rounding out the sharp corners of the geometric shape using Blade Curvature. Rotation controls the angle of the hexagon. The Specular Highlights section adds little glints to bright areas, but it's usually not a good idea to drop the value of the Threshold much below 250. Click OK to apply the effect, then clear your selection.
I try to blow out the highlights in Curves, or, you could use a "Velvia" type action to oversaturate the colors to make it look more artificial and plastic.
So basically all you're doing is making a gradient selection and then applying Lens Blur. The model-effect doesn't work if you're not shooting "down" at the subject.