I am starting to use ggplot2. I have some small n (about 30 or so) granular data with lots of overlap. Neither jitter nor alpha (transparency) are suitable. Instead a stripchart
You can use position_dodge.
position_dodge
df <- data.frame(gp = rep(LETTERS[1:5], each =8), y = sample(1:4,40,replace=TRUE)) qplot(gp,y,data=df,order=y,position=position_dodge(width=0.5))
alt text http://img100.imageshack.us/img100/8760/dodgel.png