Well, I have one.
That's pretty much it. It was a great investment a few years ago, and I use it all the time!
And by that, I mean that I use it at least twice a year.
If you have a grill, you can make it into a smoker! I've even seen online guides for getting smoke into your regular oven - google that crap and make yourself a smoker for this weekend!
Smoking food is kind of like cooking in a Crock Pot - hard to mess up, which I love! This is my method for smoking a turkey that works really well, but you can alter the cooking time or brining method to suit your needs!