OK, so it's probably a pretty rare feat in the wild, given that the stars would have to line up just right, and a horny little brookie would have to convince a ripe hen brown to drop her eggs for him rather than for a mate of the same species, but the sterile offspring of these two coldwater salmonids is a pretty cool product. Granted, most of the tiger trout found these days are planted by ambitious fisheries managers looking to either, a) remove rough fish, like chubs and suckers, from a fishery, or b) offer a unique angling experience to fishers looking for something different.
One such fishery, of the latter variety, is found high in the Pine Forest Range of northern Nevada. Blue Lake is a great high-elevation destination (and it IS a destination--you'll need a four-wheel drive vehicle, good tires and a bit of nerve) for tiger trout. Given that the lake never held a native trout population, all the fish in the small alpine lake are introduced, so tigers aren't taking a bite out of any indigenous population.
Never caught a tiger? Imagine the surly disposition of a big brown, coupled with the opportunistic nature of a brook trout, and you're pretty much there. And, since the hybrids don't spawn, they're generally interested in only one thing--eating. In fact, the first 10-inch tiger I managed to hook on a recent visit to Blue Lake was actually chased down and torpedoed by a tiger twice its size. By the time I landed the fish, it sported a fresh wound on its tail, where the bigger fish tried to take a bite.
Check with your local fish and game department to see where they're putting aggressive tiger trout, and give them a shot on a fly rod. I think, like me, you'll determine that creating tiger trout in the bowels of a fish hatchery is a pretty beneficial use of brook trout in places where brookies don't really belong.
For a better idea of what you're in for, should you want to visit Blue Lake, check out this video, produced by Trout Unlimited's Sportsmen's Conservation Project.