A simple but fun animation technique using the basic code we looked at yesterday is the endless scrolling panorama. With a bit of additional code you can also do parallax scrolling - a technique that has been used in many video games.
http://en.wikipedia.org/wiki/Parallax_scrolling
Flash tutorial:
http://www.pixelhivedesign.com/tutorials/Endless+Scrolling+Background/
(that is in Actionscript 2 - so the syntax is different from Actionscript 3 - but the concepts still apply)