Ubiquitous computing is a next generation information technology where computers and communications will be scaled further, merged together, and materialized in consumer applications. Computers will be invisible behind broadband networks as servers, while terminals will come closer to us as wearable/implantable devices, more friendly devices with sophisticated human-computer-interactions. IC chips will be implanted everywhere so that things can think and talk for distributed information processing. Key technologies here are low power, low cost, and good interface especially for wireless data communications. Low-power, high-speed CMOS circuit techniques will be presented in this paper, including low-voltage design with variable/multiple V DdV TH control, embedded memory technology for reducing capacitance, and low-switching activity design.