this is easy to do. i will take it step by step to let you in on the secret hehe, it just takes some thought.

1. pick any image you want, i will be using this image: http://www.artbeyondtheedge.com/700untitled9-9.jpg

2. open the image in photoshop and selct the crop tool

3. hold shift and drag to get a perfect square, hit enter to crop the selection


4. turn your rulers on and drag them like mine, in the middle of the image so you have 4 sections.


5. now we can use the rectangular marquee tool to select a 1/4 of the square and copy and rotate it. like so...


6. select the half you copy'd and rotated, and now do the same (except flip it vertical not horizontal) when you do the bottom half like mine.


then you can define the pattern and use it whenever. here is my final pattern...