I posted the same thing yesterday, but it went nowhere. I guess I should have included the word "FREE!" in the title.
Anyway, here it is. As the blog post explains [1], I created a small Flask app that will let you host multiple static sites/domains on one GAE instance without having to learn Git or push to Github or anything. Just download the app [2], put the static files and media in the appropriate directories, configure the URLs and deploy.
[1] http://blog.stochastictechnologies.com/easily-host-multiple-...
[2] https://github.com/stochastic-technologies/static-appengine-...