OSX eats a lot of space


I'v just got a new mac, with 30G hdd, preinstalled with OS, iLife, iWork trial, etc. It's good but consumed much of the hdd space (about 1/2 of my hdd). I've removed certain applications, like the msoffice trial, some accompanied games, the world atlas, to free some space (~2-3G). I remember i've tried to clean install tiger on another mac. The os (+xocde & X11) only took ~5G or a little bit more! Can anyone suggest ways to make a mac thinner? thank you.
If you don't use GarageBand, that takes a lot of space on a smaller drive.
Look in the /Library/Applications Support folder. You'll see the GarageBand folder taking 2 GB or more.

Something that can be a big help is to remove the language support files. A utility like MonolingualMonolingual can remove 300-700 MB of these support files.You only need these if you will be needing the foreign language menus and help support files in those languages. Cleaning these off will even make you feel a sense of accomplishment (maybe stretching it, but does make more space for you.)
GarageBand and iMovie together take somewhere between 4 and 8 GB. It's not just the apps themselves, but also support files and examples. I forget where all this stuff is, though.

After that, localizations and printer drivers are the biggest culprits. This can come to about 2 GB.