Google's App Engine "...is a developer tool that enables you to run your web applications on Google's infrastructure. The goal is to make it easy to get started with a new web app, and then make it easy to scale when that app reaches the point where it's receiving significant traffic and has millions of users."
Here (klickOnMe) you'll get a (very!) small example using GAE with Ext. Although in German I'm sure you'll get the message. English version will follow soon.