Here is a neat little trick i just discovered. These designs are just done using the Inkscape spiral tool, and a dashed stroke! Once you try it out, be sure to leave a comment showing off your spiral design!

1

How it is done:

Step 1. draw a spiral using the Inkscape spiral tool, and add more turns to your spiral  (i changed from 3 to 20):

result

 

Step 2. In the fill and stroke dialog, choose the Stroke style tab. Then bump up the stroke width (i chose 7px), and change the Dashes to something non-solid.

fillstroke

Step 3. Experiment! change the stroke width, dash style, and number of turns of the spiral:

experiment

If you want to see the settings required to make the above designs, download the SVG from the openclipart library