Comment ifolder (Score 3, Informative) 482
Novell open-sourced ifolder. there are clients for linux, windows, mac, and even iphone. Someone just needs to write a client for android.
We are implementing it on a large scale, with Active Directory integration, and 270 mobile laptop users. I understand novell is moving to neutron (their new file/folder sync technology). It should solve some of the issues we had, such as integrating with a windows server, however it will not be open-source. We just used the ifolder client, and a proxy user for everyone's folder to bypass that issue. We looked extensively for a solution, and settled on ifolder, however mobile phones weren't part of the requirement.