This is my version of it, and you can see what a dramatic quilt it is, with a strong zigzag design. To make a 48" x 48" top you will need 96 strips measuring 2.5" x 16". The more variety you have in fabrics the better. If you don't have variety I'm happy to swap strips with you on the day. This is a chance to use up any ugly fabrics you have, those 'bargain' fabrics you can't remember why you bought, but try and balance them with nice/bright fabrics, so it's not all horrid. You will need the equivalent of 12 fat quarters. (If you want to make it bigger, bring more fabric!)
If you really can't face scrappy, buy three quarters of a metre of five fabrics: this can be yardage or fat quarters. Have a good range of shades, from dark to light for a good result. Each fabric will need to be cut into 20 strips measuring 2.5" by 16".
Just to inspire you, here is another version of the same design, which makes a Scrappy Trip Round the World. Looking good! Have a look on Bonnie's site for more inspiration.
Also, some people wanted to see how to do quilt as you go, so if you can bring a couple of 'sandwiches' (6" squares wadded, backed and quilted), a strip of fabric 1.5" x 6" and one 1" x 6", then you can do it on the day and have a visible reminder of the technique.