Currently using MS Word for the bulk of my manuscript work and Dramatica Pro for outlining. On occasion, I'll also use the novel template in my screenwriting software, Screenwriter 2000. All of these are perfectly good programs (and I'm definitely not looking to "replace" my screenwriting software), but on the other hand I'm always willing to add worthwhile software to my writer's toolkit.
Lately, I've been hearing about Scrivener. The appeal seems to be that it unites a lot of the varied applications an author might use to create content. What do you, my writer friends, have to say about it? If you're using Scrivener, what do you like? What are its strengths and limitations? Is it worth buying? Please share your thoughts in the comments.