I've been guilty of accidentally adding a local configuration file into Subversion in the past. At best it will only cause another user's project or file to be conflicted or throw an error. At worst it will keep the remote project from updating as expected (causing some interesting server problems).
I've often wondered if there were a way to remove the file from the remote Subversion repository without deleting it from my local working copy. Turns out, it's a lot easier than I thought just by adding the --keep-local option.
svn rm log/development.log --keep-local
NOTE: This option is only available in versions of subversion >= 1.5.
