stripplot. Also see
panel.superposepanel.stripplot(x, y, jitter.data = FALSE,
factor = 0.5, amount = NULL,
horizontal = TRUE, groups = NULL,
...)panel.xyplot, using its jitter.x or
jitter.y argument (dependijitterpanel.xyplotx
for each level of y (or vice versa, depending on the value of
horizontal)stripplot, jitter