Well, after bitching about Mac OS X's shortcomings for a long while, I finally took the plunge and installed GNU/Linux on my MacBook. (Why it took this long was mostly because I didn't have that USB disc to backup my stuff, until now.)
In case anyone is wondering why, let me reiterate. The reason is twofold.
1. Ideology. I'm a devoted supporter of the free software movement. While Mac OS X utilises many open source components, and as a Unix system is fairly compatible with a large number of free software applications, it is still a proprietary system, and many of Apple's policies I just can't agree with.
2. Functionality. While Mac OS X is a certified Unix system, it's focus is on its own desktop environment, which doesn't intergrate perfectly with the Unix core, its command line interface or other Unix software not tailored for OS X. GNU/Linux systems (and probably most other Unix-like systems as well) are much more configurable, use the standard X Window System and are generally more 'whole', not suffering from an identity crisis as OS X is.
Debian GNU/Linux was the obvious choice, as I said before. Installing it on a MacBook isn't exactly a trivial matter, but following instructions on Debian's wiki page it wasn't actually too difficult, even though on the first try I ended up with kernel panic and had to do it all over again. In the end it booted without problems, though, and most features work fine pretty much 'out of the box'. (I still have a small partition with Mac OS X as a backup, and because a pure Debian system apparently still has some issues.)
There's still plenty of configuring to do, of course. The touchpad works, but needs tuning. I haven't been able to figure out how to get custom settings to work yet. And I haven't got wireless yet. It seems that this would require upgrading the kernel to a newer version, which is something I've never done before.
I might have been worried that I'd grown too accustomed to OS X's eye candy and convenient features. Well, I installed KDE 4, and it has certainly softened the blow. It looks pretty, and has pretty much all the desktop and window management features of OS X, such as a grid view of all the virtual desktops. And a slideshow mode for my many wallpapers.
For now, I'm just happy to be back home in a proper free software *nix.