Hypnotic Spiral

I figured out how to make this familiar shape in The Gimp.

-created a bunch of vertical lines by scaling up one of the packaged stripes patterns and saved it in my user patterns directory
- filled the document with the XL stripe pattern
- rotated stripes 45 degrees
- cropped out transparent section (had to ensure that the left and right sides matched up as if they were being tiled)
- used Distort->olar Coordinates filter to make it swirl