I just ran a manual cleanup of non-English language packs from my Applications directory. Removing the additional language junk saved 2.62 gb (yes, gigabytes) of disk space. Update: I ran it on /Library, too (same steps as below, just modify step 2), freed up another 1.1 gb, bringing the total disk space to 3.72gb.

Size of "Applications" before: 6.41 gb (6,220,745,877)
Size of "Applications" after: 3.79 gb (3,879,507,421)

Note: the following tip will permanently delete non-English language support from everything in your Applications directory. In the interest of full disclosure, I'm just pointing that out. If, for some reason, you need to recover the addtional language support (maybe you're learning Hungarian?), you'll need to re-install the application(s).

Here's what to do:

1. Open Terminal window
2. Run this: cd /Applications
3. Run this: find . -name "*.lproj" ! -name "English.lproj" ! -name "en*.lproj" -exec rm -rf {} \;

I wrote about this before -- Removing language support from OS X applications (to free up disk space) -- but just re-ran it on my current computer so made another post with current data.