My brother has a kegerator. What is a kegarator you ask? Well, in his case it's an old beaten up mustard-yellow basement refrigerator that he knocked a big hole in, installed a tap, and hooked up a 5-gallon soda keg full of his homebrew to which chills in the main compartment. In the upper freezer compartment, he stores a fresh collection of beer mugs, ready for a moments notice.
He started homebrewing in 1991 while living in Arkansas (um, we aren't talking moonshine here). It was part of a project for a German class he had in college, and he's been doing it ever since. Over the years he's brewed many a concoction, including countless ambers, stouts, ales, and other more exotic experiments like chocolate-blackberry ale, spiced winter lager, and cranberry wheat beer.
Making the simplest batch of homebrew is a lot like making a giant pot of soup, only it takes 1-2 months and you end up with fizzy bottles of it. The first step is to find the biggest stockpot you can, bring about 3 gallons of water to a roiling boil, then add malt extract and hops. Now your house should fill with a grassy, dank, sweet smell that you will either love or it with make you retch. After your "soup" boils for about an hour, it is then cooled, and strained into a glass carboy where it's topped with water (to fill up the 5-gallon vessel). Yeast is swirled into the liquid, and it's topped with a stopper and tube (called a blowoff tube).
As it sits and ferments over the next couple of weeks (during this time you will have to resort to a previously brewed batch of beer or storebought brew--fortunately these days there are plenty of microbrews to choose from), the beer will start glorping little nasty bits out through the tube. Like globs of foam and bitter oils. Once you have fermented soup, sugar is added (which will carbonate the beer when it is bottled), and the bottling begins. Oh, that's fun, let me tell you. Plan to end up a giant sticky mess. You, your kitchen, and the dog. (Hence the reason my brother has switched to kegging his brews). Assuming your bottles don't explode, they should be ready to drink in 2-3 weeks. Of course, throughout this entire process it is vital that everything remain spotlessly clean and sanitized or that first bottle of homebrew might be your last (well, that's a bit dramatic, it really can't kill you but it might make you wish you were dead).
While attending college at U of O in Eugene, Oregon, he was on a roll, brewing up to two types of beer a month and sharing it with all of his friends, using the stovetop method described above. Over the years he has refined his techniques to improve the quality of the beer. He now has an "all-grain, semi-automated beer making system" (those are his words) in his basement (did I mention he is a science geek?). Now, instead of hauling a very heavy stockpot to the stovetop and bottling the beer, it's mixed, heated, and piped into kegs all in one place. And in comes the kegerator, ready to fill your icy cold mug with frothy amber ale. It's a natural progression of beer.
If you are interested in making your own beer, which I've done myself a handful of times, there is a fantastic local beer and wine-making shop in Berkeley called The Oak Barrel. It's been around forever and they guys that work there are awesome.
p.s. The beer is damn good. good beer. yum.