I am trying to contribute to a project that uses Subversion. I used Mercurial and its hgsubversion extension to clone the repo. My work takes place on a feature branch.
I needed to figure this out for myself and wrote it up here:
http://notebook.3gfp.com/2010/05/pushing-a-new-feature-from-a-mercurial-repo-into-an-svn-repo/
I haven't yet figured out how to close a branch in subversion and have the mercurial graph look correct.