From wikipedia (on 10/19/10):
In Mormonism, Kolob is a star or planet mentioned in the Book of Abraham as the one nearest to the throne or residence of God. Mention of a celestial body by that name is found in the Book of Abraham, which is canonized by The Church of Jesus Christ of Latter-day Saints, Mormon fundamentalist organizations, the Restoration Church of Jesus Christ, and other Brighamite Latter Day Saint denominations. While the Book of Abraham refers to Kolob as a "star", it also refers to planets as stars, and therefore, some Mormon commentators consider Kolob to be a planet.
Kolob is rarely discussed in modern Mormon religious contexts, but it is periodically a topic of discussion in Mormon apologetics. The idea also appears within Mormon culture, and a Mormon hymn treats the subject. Kolob is also the inspiration for the planet Kobol within the Battlestar Galactica universe, created by Glen A. Larson, a Mormon.
According to the traditional, literal Mormon interpretation of the Book of Abraham, Kolob is an actual star or planet in this universe that is, or is near, the physical throne of God. According to Joseph Smith, Jr., this star was discovered by Methuselah and Abraham by looking through the Urim and Thummim. Mormon leader and historian B. H. Roberts interpreted Smith's statements to say that the solar system and its governing "planet" the sun, revolved around a star known as Kae-e-vanrash, which itself revolved with its own solar system around a star called Kli-flos-is-es or Hah-ko-kau-beam, which themselves revolve around Kolob, which he characterized as "the great centre of that part of the universe to which our planetary system belongs". He was confident that this hierarchy of stars orbiting other stars would be confirmed by astronomers.
The literal interpretation of Kolob as an actual star or planet has significant formative impact on Mormon belief and criticism, leading to conceptions such as that God dwells within this universe, and that the Biblical creation is a creation of the local earth, solar system, or galaxy, rather than the entire known physical reality.
Reference: wikipedia on kolob