How to “unversion” a file in either svn and/or git

Question

It happens to me all the time. I accidentally version a file, I do not want to be versioned (i.e. developer/machine specific config-files).

If I commit this file, I

Answer 1

SVN version 1.5 supports removing/deleting a file from a repository with out losing the local file

taken from http://subversion.tigris.org/svn_1.5_releasenotes.html

New --keep-local option retains path after delete..

Delete (remove) now takes a --keep-local option to retain its targets locally, so paths will not be removed even if unmodified.