appengine-filestore is a RESTful HTTP file store for Google App Engine. Kinda like a poor man's S3, but cooler. Here are the basic operations:
PUT /<filename> HTTP/1.1
...
<body>
Creates an entry for a file named <filename> with the data given by
<body> into the file store. Returns a 201 Created along with a
unique identifier (UUID) as the response body. This identifier is used
to refer to the file in subsequent operations.
GET /<uuid> HTTP/1.1
Returns a 200 OK and the contents of the file referenced by
<uuid>, or a 404 Not Found if <uuid> was not referencing any
file in the file store.
DELETE /<uuid> HTTP/1.1
Deletes the file referenced by uuid and returns a 200 OK, or a
404 Not Found if <uuid> was not referencing any file in the file
store.