How do I add diff markers to the fringe in emacs?

I'm using GNU Emacs 23, but answers for other emacsen are welcome as a jumping-off point.

For files under version control I'd like to have diff markers show up in the fringe, something like the markers that subclipse uses:

_{(source: tigris.org)}

It seems like this would be possible by parsing the output of vc-diff and using the built-in support for the fringe, but I don't want to reinvent this particular wheel unless I really have to.