How to write a facebook application
It made me
Feel Good! 
"Developed it using FBML on Google App Engine with python kay framework."
How I did it: I had an existing web application on Google App Engine that I wanted to add to Facebook Applications. It started as a iframe based app but I changed to fbml after struggling with iframe based facebook authentication and authorization.
The application is hosted on Google App Engine and developed using a MacBook with Textmate as the IDE. More features coming soon.
Lessons & tips: Do some research to decide whether iframe or fbml is the way to go for your facebook app.
Resources: Facebook developer wiki site.
Google App Engine.
Kay Framework.
Textmate.
Coffee.
