The big problem with synchronous online communication is that it doesn't
seem to scale very well. For one-on-one talking, very interesting
conversations can take place. Using the unix talk protocol, virtually
real-time talking can occur. This protocol sends each character across
the network individually so that both parties can watch words appear as
they are being typed. While this does happen to show off the typing
skills (or lack thereof) of the users, it also allows for a much more
involved conversation where one can anticipate words and sentences
before they are completed, and pauses in typing can be used for
emphasis.
However, traditional talk only works between two people which doesn't
lend itself to the notion of a group very well, and even more advanced
talk protocols only scaled to about three or four people before it
becomes too much effort to follow all of the conversations which are
occurring at one time.