I only have a 6GB HD and I've filled it up with things I don't really need...Gimp, extra languages, additional printers, etc. To uninstall these packages cleanly and quickly, just download this powerful little set of scripts called OSXGNU Package Utilities, by Chris Roberts.
Install the program, then open a Terminal window and type
sudo pkgInstall --deleteInclude a space after "--delete" (i.e "--delete "). DO NOT Press return yet! Next open the /Library/Receipts directory in the finder. Select a package to delete and drag it to the terminal window you typed the command in. You should have a line in the terminal something like
pkgInstall --delete /Library/Receipts/packagename.pkgPress 'return' and the delete process begins; if the package has a delete message you may have to respond to a yes or no question. Repeat for any other package(s) you want to delete.
Mac OS X Hints
http://hints.macworld.com/article.php?story=2002020721593298