You never realize you're low on hard disk space until you're too low -- you're trying to install an app, rip a DVD or re-sync your iPod, and all of a sudden your Mac is doing its impression of rush hour at a Japanese subway.

No matter if you're the proud owner of a brand-new MacBook or a trusty desktop iMac, here's how you can quickly and easily win back up to 8GB of free space.

The key to Operation 'Gimme Back My Hard Disk' is taking a knife to Apple's default installation of OS X. That makes this procedure especially relevant to a fresh install, re-install or upgrade.

We began with a factory-fresh install of OS X 10.4 on a MacBook.

Step 1: Mind your language
Almost every language known to man (including Klingon!) is pre-loaded onto your Mac by OS X. You'll probably only need English, so download Monolingual (free) and use it to remove everything bar the English and English Australian language modules. On our machine this handed back a welcome 2.3GB of disk space.

If there are other languages you feel you may, want keep those -- because reloading them will call for a complete reinstall of the OS.

Monolingual also offers you're the opportunity to remove architectures and input menus, but we suggest you leave these alone. The former is needed for older non-Universal apps (those not written for the newer Intel-powered Macs), while the later recovers barely 25MB. Once you set Monolingual into action it can take an hour or more to do its thing, so be patient.

Step 2: Pruning printer drivers
Apple treats printer drives the same as languages, loading up way more than you'll ever need. Once you've installed your printer, nuking the leftovers gets you back upwards of 1GB.

The secret weapon for this is Printer Setup Repair (http://www.fixamacsoftware.com/software/psr) - get the latest 5.1 version for Macs running Tiger. PSR is shareware with a US$30 rego fee but you'll need only a few minutes of the 15 day trial in order to delete the printer drivers, after which you can uninstall PSR itself.

Run the program and select Printer Drivers, then select the ones to blow away (or click the 'Select all options' button) and hit 'Delete selections'. We deep-sixed the lot and reclaimed a meaty 1.47GB.

Step 3: Axe those apps
This is where the choice of 'keep or cull' comes down to your personal habits.

You'll probably find trial editions of Apple's own Pages and Keynote programs in the iWork folder nestled inside your Applications directory. If you want 'em, hang onto 'em. But if you're happy with Microsoft Office, OpenOffice, NeoOffice or other standalone solutions (such as the Nisus Express Writer word processor), then reach for the delete key and smile as 1.3GB of space lands back in your hands. (It's not that the apps themselves are huge - most of that bulk belongs to visuals and effects for Keynote.)

GarageBand (part of Apple's iLife suite) falls into the same 'use it or lose it' category for those who aren't musically inclined, although we'll caution that it can be used to keep kids entertained for hours on a rainy day. None the less, flicking GarageBand off the stage puts around 3GB back in your pocket. The program itself is a measly 50MB - the rest comes from deleting the GarageBand support files inside the main Library / Application Support folder on your Mac (not the one inside your own user folder) and the Library / Audio / Loops / GarageBand folder. (Leave the Loops / iLife folder alone if you intend to use any of the other iLife apps, which you probably will.)

Step 4: In case of emergency
Those three surgical strikes won back 8.3GB from a fresh OS X 10.4 install on our hard disk. That's enough for us to stop there. However, if you really want some added elbow room and you've got no plans to do video editing or burn your home movies onto DVDs - which could be the case if your Mac is a work-only office machine - you could ditch iMovie and iDVD plus their respective themes (both found in the main Library > Application Support folder) to tuck an 1.7GB up your sleeve.

Before:

After: