GAE/J file store

I am working on a GAE/J based project. One of the requirements is to let the users upload files (开发者_C百科doc,ppt,pdf,xls etc).

What options do I have for storing files besides http://code.google.com/p/gae-filestore/ Is it possible to make these files "searchable"?

1. Blobstore service. It stores files up to 2GB, and its API was intended for user uploaded files. See: http://code.google.com/appengine/docs/java/blobstore/overview.html It isn't indexed, but I believe that some people have been able use Map/Reduce with it: http://ikaisays.com/2010/08/11/using-the-app-engine-mapper-for-bulk-data-import/
2. Datastore. You can store up to 1 MB as a "blob property".