xviii Personal Content Experience: Managing Digital Life in the Mobile Age GB gigabyte GEMS get enjoy maintain share GPRS General Packet Radio Service GPS Global Positioning Service GSM Global System for Mobile communications GUI graphical user interface GUID globally unique identifi er H.264 a video compression standard, part of MPEG-4 Part 10 HCI human–computer interaction HSUPA High-Speed Uplink Packet Access HTML Hypertext Markup Language HTTP Hypertext Transfer Protocol Hz hertz IC integrated circuit ID3 tagging standard for MP3 fi les IETF Internet Engineering Task Force IIM Information Interchange Model IM instant messaging IMT Internet Media Type IP Internet Protocol IPTC International Press Telecommunications Council IR information retrieval IRC Internet Relay chat ISO International Standards Organization ITU International Telecommunication Union ITU-T ITU Telecommunication Standardization Sector JEITA Japan Electronics and Information Technology Indus- tries Association JPG, JPEG Joint Photographic Experts Group LAN local area network LCD liquid crystal display LED light emitting diode LP long play record MARC machine-readable cataloguing Mbit megabit MdE metadata engine MESH medical subject headings MIDI Musical Instrument Digital Interface MMOG massively multiplayer online game MMORPG massively multiplayer online role playing game MMS multimedia messaging service MP3 MPEG-1 audio layer 3, an audio compression standard MPEG Moving Picture Experts Group