This document proposes a method for creating global maps of patent categories based on patent citation and classification data. It describes challenges in using International Patent Classification codes to group patents due to population differences between codes. The proposed solution aggregates codes to create similarly sized groups. An experiment applies this method to a dataset of European patents from 2000-2006, grouping 466 IPC codes into 35 "macro patent groupings". The results include overlays mapping the technological distances between patents held by companies like Samsung and IBM, and relating to technologies like biosensors, solar cells, and graphene. The authors conclude the method could be a new research tool, and outline next steps to improve and validate the approach.