Cozy Cloud is a french startup funded by the Mozilla startup accelerator. Cozy is open-source software they’ve released that let’s you host your own personal cloud-based services. You set it up on your server and have access to a calendar, photos, files, address book, RSS feeds and pretty much every type of cloud-based service that is supposed to synch with your computers and mobile devices.
The proposal is that by hosting your own information, it is more secure than using services. It also makes it easier to control your information by keeping in one place you can more easily get it out of and giving you the ability to destroy the whole installation with one command.
If you don’t want to manage your own server, they offer a hosted service in beta.