The restructuring of regional and national electricity markets in the U.S. and around the world has been accompanied by numerous problems, including generation capacity shortages, transmission congestion, wholesale price volatility, and reduced system reliability. These problems have created new opportunities for technologies and business approaches that allow load serving entities and other aggregators to control and manage the load patterns of wholesale and retail end-users they serve. Demand Response Programs, once called Load Management, have re-emerged as an important element in the fine-tuning of newly restructured electricity markets. During the summers of 1999 and 2001 they played a vital role in stabilizing wholesale markets and providing a hedge against generation shortfalls throughout the U.S.A. Demand Response Programs include "traditional" capacity reservation and interruptible/curtailable rates programs as well as voluntary demand bidding programs offered by either Load Serving Entities (LSEs) or regional Independent System Operators (ISOs). The Lawrence Berkeley National Lab (LBNL) has been monitoring the development of new types of Demand Response Programs both in the U.S. and around the world. This paper provides a survey and overview of the technologies and program designs that make up these emerging and important new programs.