I have been working on a side project for a bit now called We'reSICC (We are Sound Image Community & Collaboration). It planned to be an online service that is specifically designed to allow music artists and graphic artists to come together and collaborate to create music merchandise. The idea is that We'reSICC will provide a community and the necessary tools for Musicians and Graphic Artists to collaborate easily to produce merchandise and also provide the necessary tools for both Musicians and Graphic Artists to sell the products. The business model is simply that each party involved gets a chunk of the each sales profit. Anyways, thats enough lead in on that project you will find more about it later.
The reason I mentioned We'reSICC is because we recently started porting the Django code base over to Google App Engine. We soon found that it lacked support for the standard database migration support that is generally necessary when developing an application of this magnitude. Hence, after searching long and hard I came to the conclusion that I would have to throw together the basis for implementing Lazy Migrations for Google App Engine Models. Hence, I did and then handed a version with very basic functionality off to Patrick Murphy to flesh out further. Patrick Murphy is a software engineer friend of mine that is also working on We'reSICC. He has written a very nice blog post here that explains how these Lazy Google App Engine Model Migrations and provided all the code you need to get started with it. We like to give back to the community that has given so much to us, :-).
If you are interested in simply learning more about Patrick Murphy then by all means check out his blog here.