As far as I know there were 10 Dharma stations. Each station had a specific job to perform.
Arrow - has apparently been converted into a storage room. Also a part of the orientation film was hidden in this station.
Swan - The hatch to the right is the swam. The swam was planned to be a lab used for research on electromagnetism.
Flame - Dharma Initiative's communication station. It uses sonar and satellite technologies to communicate with the outside world and other stations on the Island, and can also be used to order food deliveries.
Pearl - where the Dharma Initiative studied psychology. It primarily serves as a monitoring station, to which surveillance feeds from the other stations are sent.
Orchid - features a small chamber adjacent to an exotic matter anomaly, which can be used to warp time and space. Hidden behind the chamber is a further level of the Orchid which consists of pillars and stones with unknown hieroglyphs that have been seen in a few other places on the Island, and ends with a room consisting of a giant frozen wheel built horizontally into the wall.
Lamp Post - is the only known off-island Dharma station. This station was used by the Dharma initiative to find the island. As the island is constantly moving, the researchers developed an equation to predict where the island would be in the future, thereby providing a window of opportunity to reach it.
Staff - is a medical research station, later designed to house pregnant women who were taken there to give birth and/or die.
Hydra - is a zoological research station located on a small island roughly two miles off-shore from the main island. The Hydra facility has cages outside the station in the jungle where polar bears used to be kept. An underwater complex was once used as an aquarium, which housed sharks and dolphins.
Looking Glass - is located on the sea-bed at approximately 60 feet (18m) depth, some 600 feet (182m) from the beach. The station is used to jam communications going to and from the Island, as well as generating a beacon to guide the submarine to the Island. When the Dharma Initiative was still active, the Looking Glass was used to resupply the submarine.
Tempest - is a chemical weapons development station on the Island. It is used to control the release of poisonous gases over the Island. Every day, before his death, Goodwin would travel to The Tempest to press a button to prevent deadly gases from escaping.
There you have it, a quick overview of all the Dharma stations.
In the 2008 movie Cloverfield, which was produced by J.J. Abrams and the team that made Lost, a slight variation on the Dharma Initiative logo can briefly be seen in the opening of the movie. It is during the introduction of the film which states where the "video" about to be shown came from. It is only visible for a few frames on the lower right side of screen. It looks almost identical to the Pearl station logo.
