What is telemark skiing? The telemark is a style of turn developed in Telemark, Norway. Nordic skiing is the term used for what most people think of as cross-country--the bindings don't attach your foot front and back to the ski, but only at the toe. (The binding is usually a "three-pin" binding--there are three pins on the binding that go into little holes in the toe of the boot. Hence the term "pinheads" for telemark aficionados.) The boots used are flexible and the heel is completely free. The telemark turn allows one to turn with nordic bindings.
The turn itself is very different from an alpine-style parallel turn. The outside ski is advanced and the inside ski pushed back, both knees are bent and both skis are equally weighted and edged. Hard to describe in words, but it looks very graceful.
Telemark is also harder to do decently, especially on hard-packed ski resort
runs. After two years I can finally ski the greens and some blues at resort
areas... now this probably just means that I'm an atrocious skier, but I
hope not. So why tele?
try going uphill in alpine skis?
deep powder, it's much more fun
In the intermountain west, telemark skiing really comes into its own. Endless untracked bowls of the beautiful, light, fluffy dry powder that is only found in Utah, Colorado, Idaho and Montana. Spectacular backcountry views of alpine wilderness (instead of the thousands of brightly coloured ski bums). No waiting in line for lifts. The ability to go ski-camping (or yurt-to-yurt) in the mountains. Need one say more? (And if you bring up alpine touring bindings, tele bindings and skis are much lighter.) If you want to know more, here's the Backcountry Skiing FAQ.
(Avalanches? That's all hype. You might as well worry about earthquakes
and floods in California.)