This our shooter wheel this year. It weighed a little over 4lbs and had a diameter of a little over 12 inches. This started out as a 14x14 in piece of aluminum. The outer circumference was milled out, but the spokes were cut out with a wire EDM. This is very simple compared to some of the other things on this thread, but this was the first time our team had anything EDMed and it was very cool.
http://i.imgur.com/d2bTPPE.jpg