Git-annex assistant: Like DropBox, but with your own cloud
Joey blogs his progress on git-annex assistant in detail at http://git-annex.branchable.com/design/assistant/blog/Here's a post from his personal blog that hints at how he can afford to work on this project for a year on only $20,000- http://joeyh.name/blog/entry/notes_for_a_caretaker/