I watch a local PBS station every Sat morning for tips and ideas. Last Sat there were two episodes on 18 inch blocks and directions as to how to change the them out to make very different looking quilts. This link only lists one episode but if you search I am sure you can find part 2. Very worth the watch if you are looking for a new idea.
http://www.iptv.org/series.cfm/45/se..._nancy/ep:2701