This effect works well with mystical themed wallpapers!
1: Create a new black (or dark colored) 1024x768 image. Create a new layer. On this second layer, use the line tool set at 4px and hold down the shift key to draw a straight, white line. Duplicate this layer 3 times. On the lowest line layer, Filter > Blur > Guassian Blur 8px. On the other layer, Filter > Blur > Guassian Blur 3px.
2: Select the top-most solid line layer and then Filter > Distort > Shear. Just randomly click in the Shear selection screen to create a curvy line. Right now, the line has some jagged edges. To get rid of those, Layer > Layer Style > Outer glow. Set the Outer glow to Opacity: 75%; Noise: 0; Color: White; Size: 1; Spread: 100; Range: 100 Jitter 100 and make sure Anti-aliased is checked. Duplicate your curvy line layer, remove glow effect and then Filter > Blur > Guassian Blur 9px.
3: Now, this next part, you can either choose to make your own brush, or download the one I've provided here. With the brush I've provided, in a new layer, trace over the lines so that it looks like it does in the picture.
4: Now duplicate the layer with the sparkles three times. On the bottom-most layer, Filter > Blur > Motion Blur: 90º, 40px. On the next layer, Filter > Blur > Motion Blur: 30º, 40px. On the one above that, Filter > Blur > Motion Blur: -30º, 40px. Duplicate your Motion Blur: 90º, 40px layer one time. Now it looks like a fountain of glitter.
5: Now, to fancy-up the effect a little more, duplicate your curvy line layer and Filter > Blur > Motion Blur: 30º, 200px. Duplicate the motion blurred layer again, and Edit > Free Transform and rotate this other layer in a creative way. I suggest that you also try Filter > Distort > Pinch: 100% for more fluid motion blur effects.
6: From this point on, just use your creativity and finish it however you like! I added a couple additional layers of motion blurs, and finished it by adding a new layer and setting the layer properties to color! Click the image for a larger view! Have fun with it!
Click to enlarge