It could be set up to do image resizing on the fly per URL parameters you pass to it, and storage/bandwidth is cheaper than S3 if I recall correctly. It's based on the same infrastructure as Picasa.
Edit: In fact it could be easily used to create such a service rather than having to build out the functionality oneself.
No problem, let me know how it goes, my email is in my profile. You question peaked my interest in building such a service on top of GAE with just basic API access and billing for usage. As long as you cover the hosting cost Google charges you, it'd seem to be relatively straightforward. I'm just not sure if there is enough control built in to determine what bandwidth went where.
(I expect you'd probably want to use memcache to cache images rather than the blobstore everytime, though)
(Note that you pretty much have to keep the images in the blobstore because you don't have filesystem access. You might be able to keep them in the datastore if you wanted, but those are the only two AppEngine options)
Announcement: http://googleappengine.blogspot.com/2010/08/multi-tenancy-su...
Docs: http://code.google.com/appengine/docs/python/images/function...
It could be set up to do image resizing on the fly per URL parameters you pass to it, and storage/bandwidth is cheaper than S3 if I recall correctly. It's based on the same infrastructure as Picasa.
Edit: In fact it could be easily used to create such a service rather than having to build out the functionality oneself.