The OpenCloudSync project aims to provide a data synchronization solution supporting various data stores (e.g., Dropbox, Box.net, NAS, Network shares, FTP, etc) and different devices (e.g., Linux, Mac OS, Windows, Android, ...). The goal being to free consumers from depending on a specific storage solution.
Encryption is also envisioned to protect privacy (i.e., only store encrypted content online)
Development hasn't started yet, I'm just gathering ideas so go ahead and shoot (not me preferably). Motivated people are also welcome to hop on the bus :)