The Gear Jammer Motor Works Web site has a variant movement system that uses a hex grid.
Gear Jammer Motor Works - Red Hook Autoduellists Handling Variant System
http://www.gearjammers.us/1highwayprophets/index.php
http://www.gearjammers.us/0pdf/hp_rhadruleshandling.pdf
Download the Adobe Acrobat file before the Web site disappears on December 31st.