Bascially, instant coffee is just regularly brewed coffee with nearly all the water removed. It's not that mysterious a process at all. There is no strange chemical adulteration that goes on. Instant coffee is still pure coffee.
There are two methods for producing instant coffee crystals: freeze-drying and spray-drying. The freeze-drying method preserved the most 'coffee flavour' but it's a more involved procedure. First, the coffee is allowed to sit so the water evaporates naturally, leaving a concentrated coffee solution. This concentrate is then frozen to around -40 Celsius. The remaining water freezes into ice crystals. Sublimation (a natural process similar to evaporation) is used to remove the ice. What's left is dry grains of coffee.
The second method is spray-drying. The water is again allowed to evaporate, forming a concentrate. The concentrated coffee is sprayed from a high tower in a large hot-air chamber. As the droplets fall, the remaining water evaporates. Dry crystals of coffee fall to the bottom of the chamber. The high temperatures involved in this method do tend to effect the oils of the coffee and more flavour is lost.
Even if you don't care for a whole cup of instant brew, you can still use instant coffee to add a tasty touch to other drinks, or even cooking and baking.