Create A New Document of any size, I'm using 400x400 Pixels in size, for this example.
Flood fill the background with black (#000000)
Press Ctrl + N on your keyboard to create a new layer.
Go to: Filter->Render->Clouds.
Go to: Filter->Distort->Twirl with a setting of around 236:
Press Ctrl + U on your keyboard to bring up the Hue/Saturation window and apply the following settings:
Duplicate this layer. On the duplicate layer, set its Blending Mode to "Lighten".
Press Ctrl + J on your keyboard to duplicate this layer, and change the blending mode of this layer to "lighten":
Press Ctrl + F on your keyboard to repeat the "Twirl" filter one time.
Press Ctrl + U on your keyboard to bring up the Hue/Saturation window once again, and apply the following settings:
Create a new layer.
Go to "Filter->Render->Clouds".
Go to "Filter->Distort->Twirl". and apply a setting of -236 as pictured below:
Set that layer's Blending Mode of this layer to "Lighten".
Press Ctrl + U on your keyboard to bring up the Hue/Saturation box, and check the "colorize" box and move the sliders around to get a good looking color.
I suggest choosing your own colors for this layer, and the next, as they will look good with pretty much any color.
Although, I highly suggest that you choose a light color for this effect.
Press Ctrl + J on the keyboard to duplicate this layer.
Press Ctrl + F, on your keyboard to repeat the Twirl filter once more.
Repeat Step 7, but use a different color.
You are now done!
Add some text or other stuff if you want, these look great as a banner background, or even a forum signature.