Over the past few years we've also been working on a HTTP based API for SQL databases -- <a href="http://htsql.org;" rel="nofollow">http://htsql.org;</a> it has insert/update/delete features in a plugin.
Very very cool. With a django-admin style gui, and some method of auth, this could make prototyping new apps extremely quick for legacy (or other-department maintained) databases.
Nice. I could've used this earlier. Tastypie is nice, but it really kinda assumes your models and relationships are already designed for a public API.