My grandfather could play the harmonica. And the accordion. In fact, I have his instruments, although they are in a bit of disrepair. I used to play harmonica with my old roomates back in LA, in the mid-90's. But that faded over time. Decided to finally get back into it.
Other than picking up a nice Lee Oscar Major Diatonic in the key of C, I found a swell instructional book that has both a CD, and a DVD. The DVD is great, since it visually shows the holes being played as the music is going on.
I personally like the concept of the harmonica being that it's such a small insturment: Easy to take with you, fun to play, and enjoyable to play with others. Only problem is it cuts into my other project time...
Progressive Beginner Harmonica @ www.learnToPlayMusic.com