We are participating in the biggest shift in the way computers are used since the PC was popularized nearly fifteen years ago. Employees are breaking away from the confines of their offices and taking to the road. Virtual corporations are springing up and with them the demand for new types of portable computing capabilities. As integrated circuits and microprocessors get progressively smaller, computerized intelligence is popping up in unexpected places, from mini cell phones and wristwatches to smart credit cards, telephone displays and digital ink painted on walls. The functions performed by yesterday's computers and telephones are starting to insinuate themselves into our home appliances, our office furniture, even our clothing - a concept known as "ubiquitous computing."