Shoutbox

It was done with javascript, not flash.  It's not overly difficult if you are familiar with the HTMLDOM.  There were obviously some PHP checks of the SQL database when a click was made too and all of the clicks were recorded (with some more info) in another table.

Furthermore, the images that were generated later to display where the person clicked was made through javascript as well (it just created coloured DIVs for the dots).