I have made this shape by creating a plane and grabbing the vertices and dragging them into position then extruding the region to the required thickness.
The method works but seems a little messy; is there another (easier) way of making this shape? 
If you intend on keeping your shape flat, it would be easier to draw it with Bezier curves and then extrude from there.
You probably could have traced that with bezier curves in a couple of minutes.
Here’s a tutorial: http://wiki.blender.org/index.php/Tutorials/Curves/Bézier