Putting line breaks into x-axis titles..

This would seem to work!

from here:
http://www.r-bloggers.com/line-breaks-between-words-in-axis-labels-in-ggplot-in-r/

Very useful!!

levels(birds$effect) <- gsub(" ", "\n", levels(birds$effect))
ggplot(birds,
  aes(x = effect,
    y = speed)) +
geom_boxplot()