I think you'll find that this is made up of tables.
Each element of graph is simply a table cell with a different height and color.
It is quite effective and fast but i don't beleive it is feasible to use this method to create a PIE chart.
Basically this is done on the server using some graphics technology.
Not sure if this is beyond you needs now but you can do this yourself or you can buy componenets to do the hard work for you.
You will find ASP tutorials and componenet advertising at:
They say, best men are molded out of faults,
And, for the most, become much more the better
For being a little bad.