Is there a "hello, world" for statistical graphics? In computer programming, there is a classic first program for learning/teaching a new language or system, called "hello, world".  http://en.wikipedia.org/wiki/Hello_world_program
Is there a classic first data visualization for using a graphing package?  If so, what is it? And if not, what would good candidates be? 
 A: Two thoughts:
A. When I try to get at the essence of "Hello World", it's the minimum that must be done in the programming language to generate a valid program that prints a single line of text. That suggests to me that your "Hello World" should be a univariate data set, the most basic thing you could plug into a statistical or graphics program.
B. I'm unaware of any graphing "Hello World". The closest I can come is typical datasets that are included in various statistical packages, such as R's AirPassengers. In R, a Hello World graphing statement would be:
plot (AirPassengers)  # Base graphics, prints line graph

or
qplot (AirPassengers) # ggplot2, prints a bar chart

or
xyplot (AirPassengers) # lattice, which doesn't have a generic plot

Personally, I think the simplest graph is a line graph where you have N items in Y and X ranges from 1:N. But that's not a standard.
A: The histogram of a sample of a normally distributed random variable. 
A: I think the answer is "no". That is, there is no generally agreed upon answer to your question.
@StasK points to the scatterplot.
But I'd consider what plot does in R: It depends on the data! 
You could argue that univariate statistics are simpler than bivariate ones. So... perhaps the most basic thing is a histogram; or perhaps a bar plot; maybe a density plot. 
If the point of "Hello, World!" is to show that you can make the computer do something then I'd say any plot would do. 
A: Not sure if it exactly qualifies as a hello world, but in R there are also demos built into many packages. e.g.
library(graphics)
demo(graphics)

will step the user through some basic graphics available in the package.
Just mouse click over each image to step through basic graphics illustrations.
With just two lines, the user is introduced into some
of the inspiring capabilities of R graphics for statistics.
Corresponding code to generate the graphics is displayed in the R console.

A: I would probably start with scatterplots and demonstrate the four ugly correlations.
A: I'd say there were two "Hello World" type programs for data visualization:
Print("Hello World"): Something like the histogram of a normally distributed variable, or perhaps a simple X,Y scatterplot.
For something slightly more complex, like the section where one takes the principles of Hello World and starts playing with user input, escape characters and the like, I'd say it would be playing around with the Iris data set.
