The last hour's chatterbox is graphed to clump around who was talking to whom. Sort of. This doesn't take into account message content so if you say someone's name, that doesn't hint that you are talking to them. You get points by speaking recently and within proximity to when someone else spoke.
Fullpage Chat with the graph
View the source
Incidentally, I'm bringing these links up in PMD because while the code is visible I'm not presenting complete packages so people can run this stuff on their own. In that sense its more just an introduction to another view to perlmonks.
Appended: I added the PL/R code so people could see that too. The full source code for everything is at http://grenekatz.org/downloads/chatterbox//sql/perlmonks.sql.
CREATE FUNCTION r_median(double precision) RETURNS double precision
CREATE AGGREGATE median (
BASETYPE = double precision,
SFUNC = plr_array_accum,
STYPE = double precision,
FINALFUNC = r_median
CREATE FUNCTION invisible_speakers() RETURNS SETOF text
FROM (SELECT userid
FROM chatter AS c,
( SELECT MAX( inserted ) AS s FROM other_users ) as s,
( SELECT MAX( inserted ) AS f FROM current_other_users ) AS
WHERE c.inserted BETWEEN s.s AND f.f
SELECT userid FROM current_other_users) AS i
JOIN users USING (userid);
LANGUAGE sql STABLE;