Start off by making a nice black to white gradient.

Next choose Filter > Distort > Wave and use the following settings, or choose some of your own to get a unique effect.

Next choose Filter > Distort > Polar Coordinates, and use the default settings.

Duplicate your current layer, and rotate is 90 degrees. To do this choose Edit > Transform > Rotate 90 degrees. Next change the layer mode to "Overlay"

While your still on this second layer we are going to add one more filter. Choose Filter > Distort > Twirl.

Your should have a pretty interesting design going by now, if you want to give some color to it make a new layer and change the layer mode to "color." I added a purple - blue gradient.

This is looking fairly interesting, but I'm going for more of a "vortex" feel, so lets add some depth. Once you have colored your image flatten all the layers. To do this choose Layer > Flatten Image. Now go to Filter >Distort > Pinch.

You should have something similar to the picture above!