I've been trying to find a secure method of storing files for an organisation that's distributed around the globe.
I'm aware of DropBox et al but haven't found anything that has solid security, with most of the services all that's required is a username and password and everything's wide open. Two factor authentication springs to mind but I haven't seen any services that provide this.
The organisation is using Linux, Mac and Windows machines so if there's an installable client, it should ideally work on all platforms.