Using PhoneGap + Google App Engine to Upload and Save Images
Yes, that is a fine use for GAE and GCS.  You do not need an <input type=file>, per se.  You can just set up POST parameters in your call to your GAE url.  Make sure you send a hidden key as well, and work from SSL-secured urls, to prevent spammers from posting to your app.
Goal: Take/attach pictures in a PhoneGap application and send a public URL for each picture to a Google Cloud SQL database.
Question 1: Is there a way to create a Google Cloud Storage object from a base64 encoded image (in Python), then upload that object to a bucket and return a public link?
I'm looking to use PhoneGap to send images to a Python Google App Engine application, then have that application send the images to a Google Cloud Storage bucket I have set up, then return a public link back to the PhoneGap app. These images can either be taken directly from the app, or attached from existing photo's on the user's device.
I use PhoneGap's FileTransfer plugin to upload the images to GAE, which are sent as base64 encoded images (this isn't something I can control).
Based on what I've found in Google Docs, I can upload the images to Blobstore; however, it requires <input type='file'> elements in a form.  I don't have 'file' input elements; I just take the image URI returned from PhoneGap's camera object and display a thumbnail of the picture that was taken (or attached).
Question 2: Is it possible to have an <input type='file'> element and control it's value? As in, is it possible to set it's value based on whether the user chooses a file, or takes a picture?
Thanks in advance!