It gets even better when you realize that it is not only an app engine but you get a full dashboard that shows you how many IOs your app has been requesting, how much memory and how much CPU time it has been requesting. These are all then illustrated in a nice (flash yet) dashboard for you to have an idea about your application performance.
This is a 10 min video describing how to use the Google App Engine, only if you are using Python as your programming language. Couldn’t yet find a video tutorial for Java yet. It shouldn’t be that hard though.