When TiVo's digital video recorder (DVR) hit the market in 1999, it transformed the way people watched television. No longer slaves to network schedules, viewers could watch any programs they wanted at any time of day, pause and rewind at will, and-the coup de grace-fast-forward through commercials. At the heart of the system is a computer hard drive that stores television shows as digital files; a subscription-based service updates schedules and practically does the recording for you. The company has teamed up with satellite service provider DirecTV to produce both a satellite receiver integrated with a DVR and a DirecTV high-definition DVR, to be released in April. Other DVR offerings in the market include ReplayTV and services available through cable and satellite companies.