Two weeks ago, during the CS graduate orientation at UC Davis, the IT person was showing that we have access to 50 GB on Box and UNLIMITED storage on Google Drive (I'm currently testing the limits of UNLIMITED, stay tuned). I promptly forgot about Box because I've been using Syncthing for file syncing and it's been working quite well, or at least way better than owncloud (which took infinite amounts of time to sync my stuff).
Anyway, today I was checking PaperShip (wonderful app, by the way) and noticed my Zotero free account was almost full (it is only 300 MB). I knew Zotero had WebDAV support, but I don't want to maintain a WebDAV server. Turns out Box has WebDAV support, and even found instructions on how to set everything up.