It doesn't replace the handshake, but does much more than voice alone. Mobile computing enables a person to have an office on the road. Encryption technology is controversial because it allows fully secure communications. This can be used for good or bad. On the good side is the business necessity of keeping confidential data secure.
Electronic commerce expands the market place.
The coupling of web pages to describe products with encrypted credit card payments is becoming common. In many cases this eliminates the storefront altogether. The WWW is the hottest new arrival to the desktop PC's communications capabilities. This technology opens up the world of information beyond the old fashion library. In a library, books are the primary media.