communication workplace

In what ways has technology changed communication in the workplace?
Please help me to answer this question,i can not express it well in English.
Email – the largest impact. Email has replaced phone calls, meetings, memos and face-to-face conversations. In addition to replacing earlier methods, email has its own unique abilities — self logging and mass querying for knowledge/support.
Cell phones/pagers – The ability to get in touch with someone instantly has reduced the need for redundant knowledge in a company.
MS Outlook – abitliy to book your own meetings without a secretary.
Reservationless confernce calling – When combined with email/Outlook, any individual can call a meeting at any time with any number of people in any number of locations. All without help and very little effort.
Effective Communication in the Workplace