From the website, www.mormonchurch.com, which carries this subtitle: "Created by average Mormons, with more than average time on their hands."
....how should Mormons view Muhammad? In short, Muhammad should be viewed as one who received inspiration from God to help raise a major portion of humanity to a higher level of obedience to immutable moral truths. Inevitably, this higher level of understanding and obedience has immeasurably good results for adherents who sincerely strive to live according to the moral principles taught within their faith. Therefore, Muhammad should be seen as God’s instrument to bring these people to a higher level of obedience to his will.
http://www.mormonchurch.com/37/what-do-mormons-think-of-muhammad
The Army of Israel, Joseph Smith, and Mohammed
The Danite band [which] grew to include all healthy Mormon men...was called "the Army of Israel." Joseph Smith likened himself to a Mohammed for that army, saying, "If the people will let us alone, we will preach the gospel in peace. But if they come on us to molest us, we will establish our religion by the sword. We will trample down our enemies and make it one gore of blood from the Rocky Mountains to the Atlantic Ocean. I will be to this generation a second Mohammed, whose motto in treating for peace was, "the Alcoran or the Sword." So shall it eventually be with us-- "Joseph Smith or the Sword."
(Excerpted from "The Mormon Mirage" by Latayne Scott. Joseph Smith quoted by George Hinkle, James B Turner, and John D. Lee in Brodie, "No Man Knows My History," 230-31).