I have been working on developing some RESTful Services in Django to be used with both Flash and Android apps.
Developing the services interface has been quite simp
UPDATE: Actually Manoj's solution is a bit outdated, Wad of Stuff's serializer has been left un-updated for some time and when I tried that, it seems that it does not support Django 1.6 anymore.
However, take a look at Django's official doc here. It does provide some way around using the built-in natural key. It seems that django's built-in serializer has a a little problem supporting using ImageField as part of the natural key. But that can be easily fixed by your self.