1. Make an 800 x 600 in Pixels blank page with a white background.
2. Next make sure your foreground and background colors are set to black and white.
3. Now go to Filter>Render>Clouds, you should get the basic cloud effect.
4. After you've done that go to Filter > Brush Strokes > Dark strokes Use These Settings:
5. Now go to Filter>Distort>Wave - and use the following settings
6. Now All you do is Add colour. To do so Go to Image>Adjustments>Colour Balance. And Fiddle with the colour settings till you find the right colour your after.
Your end result should look something like this:
Additional Notes: From here you can do all sorts of things to it and make it your very own funky Background Hope This Helps.
More Tutorials: 
