Every computer disaster is a learning experience. On the Mac, you can save a fair bit of space (in my case, more than 1 GB) on your hard disk if you remove extraneous languages (Traditional and Simplified Chinese, Russian, etc.) if you don't need them, using a utility such as Monolingual. That program also allows you to save even more space by removing resources your computer doesn't need, such as programming code for PowerPC processors that your Intel-based Mac doesn't use.
Unfortunately, I didn't read the fine print in the FAQ, which reads, in part:
You can use Monolingual to remove non-Intel architectures for your installed applications (even if some of the applications are PowerPC-only; Monolingual is smart enough not to remove PPC forks if those are the only ones in the universal binary). However, you should not strip the System frameworks if you want to use Rosetta. Rosetta needs the PowerPC code for all frameworks used by the emulated application...
And so, while both my Intel-based MacBook and the Intel iMac at work operate just fine, and any Intel-native software runs great, a few little programs—Photoshop, Microsoft Office, and so on—wouldn't even launch. A bit of research let me know that an Archive and Install, then a series of software updates, was my only way out, and it worked fine on the iMac. (I'm waiting to resurrect Photoshop and Office on the MacBook when I get home. In the meantime I'm typing this post on it instead.)
The metaphor is a stretch, but I feel a bit like those Macs myself these days. I need a colonoscopy to remove polyps from my intestine in a few weeks, and not long after that a surgeon will strip out a varicose vein that has returned after an initial treatment in 1994. Those fixes are, in my geeky mind, my own repairs. They remind me that my body will likely work more and more poorly in the next few decades—but there's no new model to upgrade to.
The biggest defect, of course, is my type 1 diabetes, which I've had for more than 15 years now, and for which I inject myself with insulin three times a day. Recent discoveries open the possibility of a cure from a previously unsuspected direction. But I'll avoid getting my hopes up on that one just yet—a proper system update may be available to me in a few years, or it may not.
Either way, I've got some broken bits right now, and with luck by spring they'll be fixed and I'll be on my way. That's the plan, at least.