Monolingual

Monolingual is a program for removing unnecessary language resources from Mac OS X, in order to reclaim several hundred megabytes of disk space.

I don't know about you, but I use my computer in only one language — English. So why do you have a bunch of localization files for the Mac OS X operating system filling up your hard drive? Enter Monolingual — a handy utility for reclaiming your space for more useful things. http://monolingual.sourceforge.net

Using this program freed-up about 250 megs of space on my Mac.