When I was a kid, one of the aphorisms I was taught was “never look a gift horse in the mouth.” Nobody ever gave me a horse, nor did I ever buy one or own one. So I have no idea what I would have seen if I did look a horse — “gift” or otherwise — in the mouth. But I got the basic idea: if someone gives you an ostensibly free gift, it’s impolite to inspect it so closely enough to spot its flaws, defects, and deficiencies.

In today’s world, very few of us have an interest in horses. But many of us do use a wide spectrum of Internet-based programs, applications, services, software-as-services, or whatever you want to call them … all which provide very different features and functions, but nevertheless have one thing in common: they’re free.

So we have a natural reluctance to criticize the companies who provide this free “stuff.” For example, Google Maps is so awesome that even if it’s inaccurate sometimes (as is sometimes the case when looking for specific addresses in Manhattan), you really don’t want to complain. Ditto with Firefox (and umpteen other Web browsers), Flickr (and other photo-sharing sites), YouTube, Yahoo, eBay, Facebook, MySpace, and even the stuff that Microsoft grudgingly offers to the marketplace without a price-tag. Many of these products are conspicuously described as “beta” software, even though they’ve existed in that state for a year or more; and that means we’re supposed to accept the fact that they’re buggy, incomplete, rough, and often provided with virtually no customer service or tech support.

But, hey … they’re free! And they generally provide some exciting, novel, useful features — so it would be churlish to complain, right?

Most of us would agree with this, except for one thing: some of these freebie product/services have become so useful that we’ve come to depend on them. I mean, really depend on them. It’s scary enough to think of individuals (whether freelance contractors, independent consultants, or just plain folks) who are utterly dependent on some of these products; but it’s really scary when you start thinking about the number of small businesses, with 5-10 employees, or maybe even 50-100 employees, who would literally shut down tomorrow if Google’s Gmail disappeared, or if Yahoo suffered a severe outage for a week or two.

I suppose you could make the same argument about traditional, fee-based commercial products and services, too. If I woke up tomorrow and found that Apple Computer had declared bankruptcy, and was no longer (a) supporting the hardware they’ve been selling for the past 20 years, or (b) supporting the .Mac online service that I use for my email, I would have some serious problems to deal with. Many other people would have similar problems if there were abrupt, unexpected problems with IBM, Microsoft, HP, Dell, Oracle, and others.

But while these scenarios are theoretically possible, we generally assume they won’t happen. After all, they shouldn’t happen. We’ve paid lots of money to these big companies — not only for their products and services, but also for their ongoing support. We feel that we have a right and an entitlement to ongoing service.

But Google never promised us that its email service would continue forever, or that we could continue to depend on them for maps and all the other wonderful things they provide — even the ubiquitous search engine that we’ve now transformed into the verb, “googling.” Wikipedia never promised that it would be available forever. Twitter never promised that its wonderful community-based instant-messaging service would be reliable or trustworthy, even though many of us have come to depend on it. Flickr doesn’t promise that it will keep my 13,749 photos safe forevermore; you could argue that I’m a fool to think otherwise. And the list goes on …

Unfortunately, all of us do come to depend on certain computer-based, or Internet-based, products and services for the things we do — whether it’s email, or communication, or collaboration, or music, or photos, or whatever. Some of it really is, for all practical purposes, “mission-critical”. So what should we do?

The scary thing is that most people haven’t even thought about the issue — they just assume that the “free” stuff they’ve been using will (a) always be available, (b) always be free, and (c) always be robust, reliable, scalable, and bug-free. That’s pretty naive, particularly when you consider how cynical most of us have become about the credibility, dependability, and reliability of various large institutions, especially government.

So what’s the solution? I don’t have a simple answer — other than the strong advice to (a) remember the old adage that “there’s no such thing as a free lunch,” and (b) continue monitoring the financial and technical strength, maturity, and dependability of all those free products and services that you’re now using.

The other recommendation that I would offer is this: redundancy is essential. If vendor A, who has been providing a wonderful, free, Internet-based product/service to you for the past couple of years, suddenly goes bankrupt or decides to charge you a zillion dollars a year for its product/service, then you’d better have a vendor B that you can turn to. That means you’d better find vendor B, and perhaps vendors C and D, now, just in case you need them tomorrow; and you’d better spend some time familiarizing yourself with their products and services.

The biggest problem here, as it turns out, is not just finding the existence of a vendor B, but ensuring that all of the valuable data that you’ve been keeping in vendor A’s environment can, indeed, be exported to vendor B. That’s often far more difficult than it seems, and more difficult than it should be; and in some cases, it’s downright impossible. But that’s a dangerous, dangerous position to put yourself in … as many of the Web 2.0 gurus have reminded us, it’s your data. If you can’t move your data from vendor A to some other environment, you’re screwed. And you should avoid vendor A like the plague.

Like I said, there are no simple answers — and no easy solutions. Especially in these days of rapid, chaotic technological change, life is full of compromises. But you’ve got to pay attention to this issue, and you’ve got to be willing to invest — i.e., spend real money — in redundancy, in order to keep your options open.

A small example: I love Flickr, and I’m delighted that it provides a mechanism to share my archive of 13,749 photos (which spans five generations of my family) with family members all over the world — as well as untold millions of random Internet users, who have viewed my “public” photos some 59,000 times. But I’m also aware that Flickr is part of Yahoo, and that Yahoo is now dealing with a hostile acquisition bid from Microsoft. If Microsoft succeeds in acquiring Yahoo, what happens to Flickr? I have no idea, but I have to assume the worst … which will be … well, who knows: maybe my photos would only be accessible if I was running on a Windows Vista machine, and had Bill Gates’ personal approval.

If I had more time and energy, I would upload another copy of my photo archives to an alternate service like PhotoBucket … and maybe I will someday. But for now, I’ve got a duplicate copy of the entire archive on my desktop computer’s hard disk, using Apple’s iPhoto program. And I’ve got backup copies on two other machines, plus a hard-disk backup in a safe-deposit box in my local bank. Yahoo, Apple, and Microsoft can all go bankrupt, for all I care: I’ve still got my photos.

Do you have your photos backed up somewhere? And your music? And your email? And your documents? And your calendar? And your name-address contact list? And your spreadsheets? And your other critical data? Have you really thought about what would happen if the “free” mission-critical products and services really did disappear tomorrow?