communications software for electronic and computer devices, including telephones; downloadable software for receiving, accessing, and reviewing electronic information using mobile and cellular telephones; software for data compression of electronic information for transmission to mobile devices; Software for accessing electronic information from multiple sources using push technology, including electronic mail ("email") with and without attachments, instant messages ("IMs"), personal information manager ("PIM") information related to a personal organizer, such as address book entries, calendar entries, personal notes, journal entries, and lists such as task lists, really simple syndication ("RSS") feeds, smart call messages, and short message service ("SMS") text messages; software for filtering, organizing, presenting, and personalizing electronic information from multiple accounts, senders, and Internet websites; software for previewing and reading computer files received using mobile devices; telecommunications software for using multiple networks to send and receive data with mobile devices; software for browsing the data contained on a mobile device and for browsing data obtained through Internet protocols using a mobile device; software for switching between different telephony and data transmission functions of mobile and cellular telephones