Smith and Wesson wants to give you a gun. You could win an M&P Pistol, or one of their new Pro Series pistols, and all you have to do is compete in a match with a revolver. You can also enter in the Crossover Commotion, to be eligible for that you have to compete in three state level or higher matches with a revolver, in three different sports such as IDPA, USPSA, and ICORE. You can view the rules and eligibility at the link above.
On a humorous note, there does not appear to be any rules that say you have to compete with an S&W revolver, so I guess technically you could do this with a Ruger GP100 and still be eligible to win the drawing. Skill isn’t an issue either, all you have to do is shoot, fill out the entry form, and you’re entered! Link found at Julie G’s Blog.