What is a substitute for going to culinary school? Is there?

One resource I'm impressed with is Rouxbe.com, which is an "online cooking school" with truly excellent video content. (Disclosure: I'm an affiliate, though I haven't earned anything from it - I only signed up because I think it is great, I don't refer anything just to hope to make a buck). That link will give you a 14 day free trial. The thing I like is that it is broken down into really small, highly detailed sections, and the video is HD and shot extremely close up on the hands and pots so you can really see what is happening.

Based on my reading, (Buford, Bourdain, etc.) The only way to really learn how to cook is to intern in a restaurant. It's not about recipes, it's about being forced to cut 50 pounds of onions in 2 hours, and about grilling 60 steaks in an evening. It's about being able to sense when something is done. There is no substitute for being thrown to the wolves.

I suppose you could volunteer at a soup kitchen, which would give you a near equivalent experience (although you wouldn't be exposed to the higher end of cuisine.)

The next thing you can do is eat at good restaurants. Deconstruct the dish, and try it or something similar at home.

Upvote for chris (I don't have the rep yet). Though I'm no longer in the culinary industry, I graduated from a cooking school (Scottsdale Culinary Institute) a number of years ago and worked in a couple of high-end kitchens (namely, Christopher Gross). If you want to cook at home, watch Food Network and read cooking books/magazines. However, if you think you want to cook professionally, an apprenticeship under a good chef is hard to beat. Cooking is hard work in any kitchen, but it's even harder when the standards of flavor, texture, and presentation approach perfection with every plate.

So if you fall into the latter category, my advice is to go work for the best chef you can find. Take a low wage if you have to, stay motivated, and do as many different things as you can, because you're there to learn, not fund a new television (that will come later with success).

Good luck!

Echoing a few comments above: repetition is key. Feedback is key.

And very importantly: pay attention to your food! From now on, think about everything that goes in your mouth. I mean everything. Water, toothpaste, roast beef, oranges--whatever. Pay attention to the textures, to how textures and flavours change at different temperatures, how things feel as they are chewed and swallowed. Also pay attention to scents, as scent is actually most of what we think of as 'flavour.' And also also, pay attention to food associations--how do things make you feel? What memories does this taste evoke? Paying attention to those things will help you become more creative, and aim for specific feelings and sensations when cooking for other people.

There are some key books to get as well. A good edition of Larousse Gastronimique (in French if you read it or a good English translation). Saint Julia's Mastering the Art of French Cooking. The French Laundry Cookbook. Harold McGee's On Food & Cooking: The Science & Lore of the Kitchen.

And then if you want to get really crazy and spend monstrous amounts of money, get the Fat Duck cookbook, and the elBulli series of books (which will set you back only slightly more money than I make in a month. They are frighteningly expensive, which is why I do not yet own them).

Watch some, very selective, shows on the Food Network: Ina Garten (Barefoot Contessa), old reruns of Nigella Lawson (not her latest couple of series, which are only barely a step above boil-in-the-bag), old Mario Batali. Laura Calder, if you get her show in the USA, is (despite her protestations) a professionally-trained cook who is obsessed with French food and technique. The F-Word is also surprisingly good for actual recipes presented with not much fuss.

Watch, on YouTube: Saint Julia, Jacques Pepin.

Practice, practice, practice, practice. Want to get good and fast at chopping onions, carrots, whatnot? Buy a case of onions, process them all at once. (Helpful hint: chill them first; less crying). Make a gigantic pot of soupe a l'oignon les Halles, freeze whatever you can't use immediately. Do the same with carrots, with cucumbers, with bell peppers. (Well, don't make the same soup obviously).

Get good equipment. Good knives--you don't need to go and buy a set of Globals, obviously, but get good knives. Discard gadgetry from your kitchen--I'm not saying get rid of your potato masher; it's a great tool. But ditch the egg separator--your hands are the best egg separator there is.

Shop well. Find local suppliers wherever you can. When you're buying fruit and vegetables, get up close and personal: touch them, smell them, taste them if it's an option before buying (in my experience, farmer's markets will be really good about letting you slice something open once they get to know you). Then in the kitchen, let the ingredients speak to you.

All of these things will help you become a much, much better cook. But as mentioned by Dinah, the only way to get to a professional level is to cook with, for and be cooked for by cooks who are better than you are.

As you're assessing your resources, remember that the one thing school always gives you, books can't give you, and the internet rarely gives you: feedback.

For casual learning, books and trial and error are fine. Since you specifically asked about the caliber of skill that comes from culinary school though, you'll want feedback from people who are more advanced than you are, not just information. (Sites like this one are certainly a start.)