VLSub on the Videolan addons page was recently updated, with new search options.

Subtitle Finder: Get the subtitles of movies from the internet, currently only from OpenSubtitles.org (just displays subs, doesn't saves them).
An advanced Subtitle Finder (Windows&Linux) modified version to save subtitles can be downloaded here, and is currently developed and discussed here -

I like to use them both in parallel, although the latest updated version of VLSub has equaled the advantage that Subtitle Finder had before, as the two projects seem related.
So, keep an eye on their latest versions.
How to install lua scripts in vlc:
Windows (all users): %ProgramFiles%\VideoLAN\VLC\lua\extensions.
Linux (current user): ~/.local/share/vlc/lua/extensions/.
Mac OS X (all users): /Applications/VLC.app/Contents/MacOS/share/lua/extensions/