I few weeks ago I discovered tailor. After installing the latest tarball. Following this tutorial I was able to checkout from a svn repository from work into my hg repo. I was not interested in pushing back changes, in my case the project ended, however it should be easy enough to do.
I called my config file: projectname.tailor
root-directory = /home/me/projectname
source = svn:projectname
target = hg:projectname
state-file = svn-to-hg.state
repository = https://svnserver/svn/main/projectname
module = /trunk
subdir = svnside
trust-root = True
repository = /home/me/projectname
subdir = hgside
At the terminal:
$ tailor --configfile=projectname.tailor svn-to-hg
This will create two directories in /home/me/projectname/ hgside and svnside.