Start a new document. I used 800x800.
Go to Edit->Fill, use: Pattern, select custom pattern and choose this one:
Now go to Filter->Distort->Polar Coordinates
Options: Rectangular to polar.
Then apply. Filter->Distort->Pinch, Set amount to 100%
Then Press CTRL+F 3 times to reapply the filter.
Now apply: Filter->Distort->Spherize. Set amount to -100%
Then reapply by pressing CTRL+F about 3 times (its up to you).
You will probably notice the edging near the corners, to remove this, make a selection like the image on the left:
Then go to Select->Inverse
Then go to Filter->Blur->Radial Blur
Blur Method: Zoom.
That's it, just apply colors using hue and saturation and use it for your backgrounds/wallpapers.