Here are some pictures, as promised. There are more in an album on my Facebook page: https://www.facebook.com/VCreeper (If you're not on Fb but would like to see the other pics, just let me know and I'll send them to you :) )
I found the pattern for this project over at http://duringquiettime.blogspot.co.uk/2009/10/scrappy-armrest-pincushion-tutorial.html. The tutorial tells you how to make the armrest pincushion itself, but the block designs are up to you. I'm loving it!