I just came by the following plot:

And wondered how can it be done in R? (or other softwares)
Update 10.03.11: Thank you everyone who participated in answering this question – you gave wonderful solutions! I’ve compiled all the solution presented here (as well as some others I’ve came by online) in a post on my blog.
Make.Funny.Plot does more or less what I think it should do. To be adapted according to your own needs, and might be optimized a bit, but this should be a nice start.
EDIT : corrected so it always works.