This document discusses trends in data center efficiency practices. It outlines Sun Microsystems' data center efficiency practice which includes design, build, relocation, standardization, consolidation, and virtualization of IT infrastructure as well as modernizing operations. The practice follows a methodology of phases and uses building information modeling. It also discusses alternative power supplies, the uniqueness of each customer, and trends like increased focus on power and cooling, improved metering, and acknowledgement of external support. An example Dutch project combines data centers with cloud computing and the provisioning of power, networking, heat, and energy from waste-heat-krachtwerken units.